Conspiracy and Social Movements

Steffen Seitz* February, 2026

Conspiracy prosecutions of social movements are on the rise. From anti-“Cop City” protesters in Atlanta to pro-Palestinian protesters in California, prosecutors are increasingly wielding conspiracy law to suppress social movements. This development is troubling. Social movements have long served as vital engines of democratic self-governance; they crystallize issues, foster public discourse, and mobilize citizens. Yet conspiracy law endangers these movements—and thus democracy—by targeting what makes them work: public expression and social ties between activists.

This Article makes three significant contributions to our understanding of this threat. First, it demonstrates that a charge of conspiracy requires remarkably little—just the appearance of concerted action and an opportunity to create or join a joint scheme. This loose definition of the conspiratorial agreement enables prosecutors to criminalize mere proximity to protest activity and mere sympathy with a movement’s aims. Second, this Article explains why contemporary social movements are especially vulnerable to conspiracy charges. Like their historical counterparts, contemporary movements fundamentally depend on strong social ties between activists. But unlike their predecessors, which built capacity slowly and methodically, today’s movements can use social media to quickly mobilize on a large scale without first building internal competencies. Today’s social movements also generate more public expression than ever before. Conspiracy law weaponizes these dynamics, targeting the strong social ties that sustain these already fragile movements while twisting activists’ public expressions into evidence of criminal intent. Third, drawing on several recent case studies, this Article demonstrates how conspiracy prosecutions exploit these vulnerabilities and undermine entire movements by chilling participation and eroding trust between activists.

Existing doctrinal safeguards fail to protect contemporary social movements from these dangers. Accordingly, this Article advocates a bold solution: effectively abolishing conspiracy charges for social movement conduct by removing certain predicate offenses from the scope of conspiracy. This reform would help preserve the vital role of social movements in American democracy without unduly sacrificing public order.

Introduction

Forest defenders in Atlanta.¹ Pro-Palestinian protesters across California.² Antifascist counter-protesters in San Diego.³ Pro-life activists in Washington, D.C.⁴ Animal activists in Sonoma County.⁵ Water protectors in North Dakota.⁶ Anti-racist protesters in Santa Barbara.⁷ Native American activists in upstate New York.⁸ Anti-Trump protesters in Washington, D.C.⁹ In each of these recent cases, activists found themselves charged with criminal conspiracy. This trend reveals an alarming new prosecutorial playbook, one in which prosecutors increasingly wield conspiracy law to suppress social movements.

Conspiracy law is notoriously broad and ill-defined. As Justice Robert Jackson aptly noted, in a sentiment since echoed by numerous courts and scholars,¹⁰ the “crime of conspiracy is so vague that it almost defies definition.”¹¹ The centerpiece of conspiracy law is the criminal agreement: Typically, two or more individuals must agree to commit a crime, ¹² but the nature of the criminal agreement is woefully underspecified. As this Article shows, the criminal agreement, as prosecuted, usually requires no more than the appearance of concerted action and an opportunity to create or join a joint scheme. This is an exceptionally low bar.

Conspiracy’s low bar poses a unique danger to contemporary social movements. A social movement is a collective campaign that challenges the status quo through displays of “numbers, commitment, unity, and worthiness.”¹³ Paradigmatic examples include the civil rights, women’s rights, and labor movements.¹⁴ Like their forebears, contemporary social movements fundamentally depend on strong social ties between activists. Social ties create the conditions for activists to engage in highly communicative “high-risk” activism—like nonviolent direct action—and spread new ideas, behaviors, and norms.¹⁵ But unlike movements of the past, contemporary movements are unusually horizontal and decentralized. Social media enables today’s activists to mobilize rapidly and en masse, without the tedious capacity-building that once took significant time and resources.¹⁶ Although contemporary social movements can therefore emerge onto the national stage more quickly, they are also more fragile because they lack the internal competencies to contend with unexpected challenges. The resulting social movements appear large and well-coordinated but are actually more vulnerable than ever before.

Conspiracy poses an existential threat to contemporary social movements by targeting precisely what makes movements work: their strong social ties and public expression. The conspiratorial agreement’s vague definition enables prosecutors to cast a wide net—turning proximity, sympathy, and even lawful collaboration into circumstantial evidence of a crime. For decentralized movements already vulnerable to government repression, the chilling effect of conspiracy charges can unravel the trust and cooperation necessary for their survival. The stakes extend beyond any individual movement. Conspiracy charges decimated the grassroots animal rights movement for over a decade¹⁷ and now similarly threaten burgeoning movements like student advocacy for Palestine and the “Stop Cop City” campaign in Atlanta.¹⁸

As forms of collective action and political agitation, social movements are vital to American democracy. From civil rights to environmental justice, social movements have crystallized issues, forged collective identities, and mobilized citizens.¹⁹ They are self-government in action and at the very core of what our legal order—and the First Amendment in particular—should protect. Conspiracy’s threat to social movements is a threat to American democracy itself.

Although scholars have written extensively about conspiracy law’s defects,²⁰ and some have even considered these defects in the First Amendment context,²¹ this Article is the first to focus on the specific threat conspiracy poses to social movements. Unlike prior scholarship, which takes for granted that expression unprotected by the First Amendment can be criminalized without further scrutiny,²² this Article argues that we must consider not just whether certain activity is criminalized but also how it is criminalized. When wielded against activists, conspiracy law criminalizes in a manner that can undermine and chill social movements. Given the importance of social movements to American democracy, this threat demands urgent attention.

This Article proceeds in six parts. Part I examines recent applications of conspiracy law to social movements, with a particular focus on the RICO prosecution of Stop Cop City activists in Atlanta, Georgia. Part II analyzes the structure of modern conspiracy law. It argues that current doctrine requires nothing more than the appearance of concerted action and an opportunity to create or join a joint scheme. Part III then analyzes the structure of contemporary social movements, which are increasingly leaderless and horizontal, while still dependent on strong social ties between activists. Part IV is the heart of this Article. It combines the insights of the previous parts and argues that conspiracy poses a unique and overriding threat to social movements. The ill-defined agreement element of conspiracy makes it all too easy for prosecutors to criminalize proximity to “bifarious” movements that contain both legal and illegal elements.²³ Part V then demonstrates that existing safeguards are inadequate to protect contemporary social movements. Finally, Part VI offers a bold, new solution: effectively abolishing the application of conspiracy to social movements by removing certain predicate offenses from the scope of conspiracy.

I. The New Prosecutorial Playbook

Prosecutors are increasingly using conspiracy to target social movements, but the tactic is hardly new.²⁴ Conspiracy has long been used against dissidents. In fact, conspiracy law took its modern shape in response to labor organizing in the nineteenth century.²⁵ In an effort to stamp out “dangerous combinations” of workers, conservative courts shifted the focus of conspiracy doctrine from the substantive evil that was the goal of the agreement to the formation of the agreement itself.²⁶ Conspiracy was then repeatedly deployed against dissenters in wartime: anarchists, communists, and other anti-war campaigners in World War I; Communist Party members during the Cold War; and anti-war protesters during the Vietnam War.²⁷

Today, we recognize many of these prosecutions as troubling infringements on liberty.²⁸ Modern courts would likely decide these cases differently,²⁹ and much of the architecture of contemporary First Amendment law is a direct response to the excesses of these wartime prosecutions.³⁰ But in recent years, conspiracy prosecutions of social movements seem to be on the rise again.³¹

Likely the most prominent prosecution of a social movement today—and one that exemplifies the problem more generally—is the RICO prosecution of the so-called “Stop Cop City” movement in Atlanta, Georgia. The movement began in 2021, shortly after the Atlanta City Council proposed leasing a tract of forested public land to the Atlanta Police Foundation to build a police training facility—or “cop city” in the activists’ parlance.³² A loose, ad hoc coalition of individuals and organizations, many of whom had begun working together following the police killings of George Floyd and Rayshard Brooks, came together to oppose the project.³³ Their activism took myriad forms: petitioning for a referendum on the project, posting on social media, putting up flyers, organizing rallies, and occupying the forest.³⁴ Some also engaged in acts of sabotage and property destruction.³⁵ Various organizations supported the activism, including the Atlanta Solidarity Fund, which coordinated bail and legal representation for detained protesters.³⁶

The campaign met with fierce resistance from law enforcement. Police killed an activist occupying the forest—who, an independent autopsy showed, was simply sitting cross-legged with his hands up—before bulldozing the forest encampment.³⁷ Forty-two activists were arrested in the sweep and charged with domestic terrorism for alleged acts of vandalism. For nearly three months, three activists were jailed for distributing flyers.³⁸

Then, on August 29, 2023, sixty-one activists were indicted under Georgia’s RICO statute for allegedly conspiring to stop the construction of the police training facility.³⁹ The indictment does not hide that it is targeting a social movement. It begins with a lengthy section on anarchism, defining the terms “collectivism,” “mutual aid,” and “social solidarity.”⁴⁰ Though recognizing that the Stop Cop City movement “does not recruit from a single location, nor . . . [does it] have a history of working together as a group in a single location,” the indictment argues that “the group shares a unified opposition to the construction of the Atlanta Police Department Training Facility.”⁴¹ In other words, what serves as the basis of the conspiracy—what brings individuals within the scope of the criminal enterprise according to the indictment—is their shared political goal. The overt acts of the “conspiracy” are predictably heterogenous as a result and include everything from writing “ACAB” (short for “All Cops Are Bastards”) or buying glue to arson.⁴²

Property destruction, trespassing, and true threats are, of course, unprotected activities under the First Amendment and therefore subject to criminal regulation. What makes the Stop Cop City RICO prosecution troubling is that it transforms a loose coalition of activists using “multiple grammars of struggle” into a single criminal conspiracy, unified only by a political goal.⁴³ Under this legal theory, any activity evincing opposition to the police training facility can suddenly become evidence of serious criminality and subject an individual to penalties generally reserved for serious criminal acts. Indeed, the RICO defendants facing sentences of up to twenty years in prison include individuals who allegedly did nothing more than distribute flyers or manage a bail fund.⁴⁴

While the Stop Cop City prosecution may be the most prominent recent example of prosecutors using conspiracy as a tool to crack down on a social movement, it is far from the only example. As pro-Palestine protests have swept the country, prosecutors have increasingly responded with conspiracy charges. Eight protesters who blocked the Golden Gate Bridge, for example, were charged with felony conspiracy.⁴⁵ Twelve other pro-Palestine protesters who occupied a vacant UC Berkeley building were also charged with conspiracy,⁴⁶ as were pro-Palestine protesters who occupied part of a parking garage at UCLA.⁴⁷ Similarly, animal activists in California have been charged with felony conspiracy for “open rescues,” in which they entered a factory farm, documented the conditions, and removed a small number of sick or injured animals.⁴⁸ The activists brought the animals to a vet and then a sanctuary, after which they published their footage widely, baring their names and faces to the public.⁴⁹ Prosecutors brought felony conspiracy charges in addition to charges for substantive offenses like trespass, theft, and burglary.⁵⁰ And recently, pro-life activists who blockaded an abortion facility in Washington, D.C. were convicted of conspiracy last year. Their blockade, which briefly shut down the facility and resulted in a nurse spraining her ankle during the chaos, resulted in record sentences, including a nearly five-year federal prison sentence for the action’s organizer.⁵¹

These conspiracy prosecutions are historical anomalies. As a demonstrative comparison: When hundreds of protesters occupied California university buildings in 1964, some were charged with substantive crimes such as trespass in a public building, failure to disperse from an unlawful assembly, and resisting arrest—but none were charged with conspiracy.⁵² Likewise, when open rescuers removed animals from factory farms in 2004, 2016, and several times in 2017, they were charged with various crimes but never conspiracy.⁵³ And while abortion clinic blockades have long been a tactic of the pro-life movement—in 1989, for example, over 12,000 people were arrested at 201 blockades⁵⁴—the recent conspiracy prosecution in Washington, D.C. marks the first time that an activist has been sentenced for conspiracy under a federal civil rights law.⁵⁵ Although conspiracy prosecutions of social movements are not new, these historical comparators reveal an ominous shift and escalation in the tactic’s use.

To be clear, this Article does not contend that blockades and occupations must be tolerated when done for political ends. Trespass, vandalism, and burglary are crimes that apply to activists and non-activists alike. Notably—and, as this Article argues, troublingly—prosecutors are increasingly reaching for conspiracy to address nonviolent direct action by activists. In the cases discussed so far, as in so many social movement prosecutions,⁵⁶ conspiracy charges were brought after the underlying substantive crime was already committed. Put differently, prosecutors in social movement cases are not opting for conspiracy charges because they are otherwise without tools to address crimes. Prosecutors are opting for conspiracy charges because conspiracy law provides the path of least resistance to sprawling liability and has the highest likelihood of neutralizing a social movement. It is because of conspiracy’s chilling effect on activism—not despite it—that prosecutors bring such charges. The remainder of this Article examines the structural features of conspiracy law that enable this prosecutorial approach and explains why it poses a unique threat to contemporary social movements.

II. The Structure of Conspiracy Law

Having outlined the resurgence of conspiracy prosecutions against social movements, the next step is to explore the legal elements of conspiracy that enable this prosecutorial approach. Typically, to convict a defendant of conspiracy, the state must show that: (1) the defendant agreed with at least one other person to commit a crime,⁵⁷ (2) the defendant had the specific intent to join the unlawful agreement and further its unlawful purpose, and (3) one of the members of the conspiracy performed at least one overt act in furtherance of the conspiracy.⁵⁸ This Part examines the rationale underlying conspiracy and its three component elements, demonstrating how their vagueness and malleability have reduced them to near-nullities.

A. The Rationale of Conspiracy

Conspiracy law is traditionally justified by reference to the unique danger posed by secretive agreements. As the Supreme Court has explained, concerted action to commit a crime is more dangerous than ordinary, unilateral offenses and more likely to escape detection.⁵⁹ Furthermore, groups foster social identities that can encourage risky and harmful behavior.⁶⁰ As a result, members of a conspiracy are more likely to commit offenses that they would otherwise shy away from, and they are less likely to desist once they have embarked on “their path of criminality.”⁶¹ Conspiracies also create economies of scale that allow coconspirators to achieve their goals more efficiently and effectively while evading detection. For instance, conspirators can take advantage of their numbers to (1) specialize and more quickly achieve their crimes; (2) overwhelm law enforcement resources in a particular area; and (3) use lookouts, getaway drivers, and other specialized actors to escape.⁶² Conspirators can also discipline one another to prevent defection and ensure that the criminal goal is attained.⁶³ The rationale for conspiracy law thus emphasizes two features of conspiracies: They pull multiple people together and benefit from group dynamics, and they are organized in secret, which better enables their members to evade detection.⁶⁴

Given these dangers, conspiracy law targets the secretive agreement itself, which is “a distinct evil” and “may exist and be punished whether or not the substantive crime ensues.”⁶⁵ Drawing on social science research, Neal Katyal argues that conspiracy law is virtually tailor-made to combat the two risks criminal agreements pose: cooperation and secrecy.⁶⁶ Conspiracy law forces conspirators to adopt inefficient practices and promotes information extraction, thereby turning the group dynamic from an asset into a liability.⁶⁷ Though even Katyal acknowledges that conspiracy can shade into collective punishment, he nonetheless argues that the crime is justified because of the significant dangers posed by concerted, secretive actions.⁶⁸

For these reasons, joining a conspiracy—an expressive act that facially implicates the First Amendment⁶⁹—is categorically unprotected speech.⁷⁰ Such speech “has no social value” and thus traditionally receives no First Amendment protection.⁷¹

B. The Elements of Conspiracy

1. Agreement

First and foremost, conspiracy requires at least two persons to form an agreement to commit an unlawful act or a lawful act by unlawful means.⁷² As various courts have put it, agreement is the “essence of the crime,”⁷³ “[t]he gist of the offense,”⁷⁴ “the core” of the wrongdoing,⁷⁵ and “the heart of . . . conspiracy.”⁷⁶ Most pithily, “The crime of conspiracy is the agreement itself.”⁷⁷

The agreement justifies many of the so-called “incidents” of conspiracy, such as more permissive rules of evidence and more expansive liability.⁷⁸ Under the Federal Rules of Evidence, for example, a statement made by a “coconspirator during and in furtherance of the conspiracy” is not hearsay.⁷⁹ The agreement effectively creates an agency relationship among the coconspirators, so the words of the agent-coconspirator can be attributed to the principal-coconspirator—even if the statements were made before the defendant joined the conspiracy.⁸⁰ Similarly, the agreement underpins Pinkerton liability, where conspirators are deemed “partner[s] in crime,” liable for the reasonably foreseeable acts of other coconspirators done in furtherance of the conspiracy.⁸¹ The agreement is so powerful that it justifies attributing not only the words of one coconspirator to another, but also their acts—even if such acts are criminal.

But despite its centrality in conspiracy law, the nature of the conspiratorial agreement continues to vex courts and scholars alike because of the challenge in actually defining such agreements.⁸² Both the Supreme Court⁸³ and numerous lower courts⁸⁴ have used contractual language to describe the agreement, often saying it amounts to a “meeting of the minds.” But courts have also held that coconspirators do not need to know each other to form an agreement,⁸⁵ and that even a slight connection⁸⁶ to the conspiracy can be enough.⁸⁷ The agreement need not be formal or express⁸⁸—“a tacit or mutual understanding among the parties will suffice”⁸⁹—and the jury can rely exclusively on circumstantial evidence.⁹⁰ But the evidence must also be “clear, not equivocal . . . . [B]ecause charges of conspiracy are not to be made out by piling inference upon inference.”⁹¹ These conflicting pronouncements form a body of law that is both vague and irreconcilable.⁹²

This confusion spills over into jury instructions, which give little guidance on the central element of conspiracy law. Consider California’s jury instructions:

The People must prove that the members of the alleged conspiracy had an agreement and intent to commit <insert alleged crime[s]>. The People do not have to prove that any of the members of the alleged conspiracy actually met or came to a detailed or formal agreement to commit (that/one or more of those) crime[s]. An agreement may be inferred from conduct if you conclude that members of the alleged conspiracy acted with a common purpose to commit the crime[s].⁹³

This instruction, like the underlying case law, is equivocal. It provides little help in resolving tricky cases and, as we shall see, makes it easy for a jury to project a conspiracy onto conduct with little more than the mere appearance of joint action.⁹⁴

To better define the agreement element, it is fruitful to consider what evidence courts have held sufficient to prove the element in borderline cases.⁹⁵ These decisions reveal what minimal evidence courts will accept. Such an analysis reveals that a conspiratorial agreement only requires concerted action and an opportunity to create or join a joint scheme. Concerted action means action that appears coordinated. An opportunity to create or join a joint scheme means a window of time—however brief but more than an instant—in which an individual could reach a mutual understanding with at least one other person. To clarify this definition, consider the following two illustrative cases with near-identical facts but different outcomes.

In Griffin v. State, the Arkansas Supreme Court considered whether a mob assault on two police officers evinced a conspiratorial agreement.⁹⁶ The officers arrived at the scene of a car accident where a large crowd had gathered. The defendant attacked one officer, after which the crowd “swarmed” both officers. After the defendant was convicted of conspiracy to assault a police officer, he raised the question of whether this meager evidence sufficed to establish an agreement.⁹⁷ The Arkansas Supreme Court held that it did. The Court reasoned that the evidence was sufficient because “two or more persons pursued by their acts the same unlawful object, each doing a part, so that their acts, though apparently independent, were in fact connected.”⁹⁸ In other words, there was sufficient evidence to find concerted action. Just as importantly, the Court went on to hold that the timing of the assault permitted an inference of agreement too.⁹⁹ The police officers had arrived after the defendant and crowd had been gathered for some time.¹⁰⁰ As the Court noted: “It would be extremely difficult, if not impossible, to ever produce direct evidence of a conversation or meeting among the assaulters during the period intervening between the call to the officers and the alleged challenge given them by [the defendant].”¹⁰¹ Even without concrete proof of an agreement, the combination of concerted action (the crowd joining the assault after the defendant’s initial attack) and an opportunity to create a joint scheme (the unaccounted-for time before the officers’ arrival) was sufficient to permit the finding of a conspiratorial agreement.

Meanwhile, in People v. Butts, a California Court of Appeals faced similar facts but reversed a conspiracy conviction for lack of an agreement.¹⁰² The two defendants in Butts got into a verbal altercation with a group of boys, after which the boys challenged the defendants to a fight. The defendants “walked side by side and followed” the other boys from a café into an empty lot, where a fight ensued, resulting in one boy’s death and severe injuries to two others.¹⁰³ Like in Griffin, the Court in Butts had to decide whether the defendants’ seemingly coordinated action amounted to an agreement. Unlike Griffin, however, the Court in Butts answered this question in the negative. Although there was “simultaneity,” which ordinarily is enough to establish coordination, “the defendants d[id] not initiate aggressive action but [were] themselves challenged to fight.”¹⁰⁴ The Court considered each of the defendants’ actions—exiting the café together, following the other boys to the empty lot, and fighting as a team—but held that “[n]one of these actions supplies any inference of a preexisting agreement, however brief, between these defendants to initiate aggressive action.”¹⁰⁵ Even though there was concerted action—just like in Griffin—the Court held that there was never an opportunity for the two defendants to create or join a joint scheme. The other boys issued a challenge, and the two defendants in Butts responded to that challenge immediately, leaving no moment, “however brief,” to reach a mutual understanding.

The dispositive difference between Griffin and Butts appears to be that the former included a window of time in which an agreement could have been reached, while the latter did not. Though the window for agreement can be brief, it cannot be instantaneous.¹⁰⁶

As we have seen, although jury instructions nominally require finding a “common purpose” or “criminal partnership” before an agreement can be said to exist, these terms are subject to a mountain of caveats that render them vague and malleable.¹⁰⁷ Taking these convoluted and pliable instructions, the jury can—and is, in fact, almost encouraged to—project a conspiratorial agreement onto the mere appearance of concerted action whenever some window of time exists in which defendants could have formed or joined a joint scheme. Thus, the rule synthesized from Griffin and Butts effectively defines what the agreement actually amounts to in conspiracy law: concerted action plus an opportunity to create or join a joint scheme. The ultimate result is that the agreement element—the supposed “heart” of conspiracy law¹⁰⁸—provides remarkably little constraint on conspiracy prosecutions.

2. Intent

Conspiracy’s mens rea is closely related to its agreement requirement. Conspiracy is a specific intent crime,¹⁰⁹ requiring intent in two regards: the intent to join the criminal agreement and the further intent to achieve the agreed-upon crime.¹¹⁰ Conspiracy’s specific intent requirement is commonly seen as a bulwark against governmental overreach and abuse.¹¹¹ It ensures that only those who are actually culpable can be convicted: Fellow travelers and hangers-on who merely associate with conspirators should be able to escape liability because they lack the requisite specific intent.¹¹²

But contrary to this common wisdom, the intent element provides very little protection against prosecutorial overreach. The agreement element’s indeterminacy inevitably infects the intent element. If what one joins is uncertain, then whether and how one has joined becomes uncertain too. Because the agreement’s contours are vague, the prosecution faces a significantly lower hurdle in convincing a jury that a defendant specifically intended to join that ill-defined enterprise. Combined with conspiracy’s permissive evidentiary rules, this looseness makes it remarkably easy for juries to convict unsavory defendants for mere association. For example, in Griffin, there was no evidence that a plan to attack the police actually existed, that the police had been lured out, or that the defendant was connected to any other member of the crowd.¹¹³ When an unsympathetic defendant acts wrongfully, it is all too common for a jury to also infer a sinister and secretive conspiracy—and courts will do little to correct them.¹¹⁴

Paradoxically, focusing on intent may actually increase the likelihood of guilt by association in some cases. For instance, speech supportive of alleged coconspirators, or any generalized association with alleged coconspirators, may be deemed circumstantially relevant to prove intent to join a conspiracy.¹¹⁵ On that basis, courts have permitted a wide range of associational evidence in conspiracy cases, including footage of codefendants appearing together in a music video,¹¹⁶ posts from social media accounts expressing support for an alleged coconspirator,¹¹⁷ and evidence that a defendant wore the color red.¹¹⁸ A jury inundated with such evidence may be quick to infer conspiratorial intent, especially when the speech or association is itself prejudicial.¹¹⁹ Instead of being a shield against guilt by association, the intent requirement becomes a cudgel.

Appellate review, unfortunately, provides little accountability here—and may even make things worse. Appellate courts are unusually deferential to conspiracy convictions.¹²⁰ As the Second Circuit explained:

This high degree of deference we afford to a jury verdict is especially important when reviewing a conviction of conspiracy. This is so because a conspiracy by its very nature is a secretive operation, and it is a rare case where all aspects of a conspiracy can be laid bare in court with the precision of a surgeon’s scalpel.¹²¹

Other courts have echoed this sentiment.¹²² Instead of policing jury verdicts to root out guilt by association, appellate courts simply ratify the verdicts: As long as a reasonable juror could have inferred an agreement and intent, the conviction will stand,¹²³ which enables more verdicts with little basis in the future.¹²⁴

Finally, even though purposeful intent is required to join a conspiracy, further liability for crimes growing out of the conspiracy require only negligence.¹²⁵ A defendant can be found guilty of a serious crime—even murder¹²⁶—without even being aware that the crime occurred.¹²⁷ In short, conspiracy’s intent element does little to protect against guilt by association, and all too often it actually facilitates such guilt.

3. Overt Act

The final safeguard against overbroad application of conspiracy is the overt act element, which requires at least one member of the conspiracy to engage in an “overt act” in furtherance of the conspiracy.¹²⁸ In theory, the overt act requirement provides “an opportunity for the conspirators to reconsider, terminate the agreement, and thereby avoid punishment for the conspiracy.”¹²⁹ But in practice, the requirement is another “virtual nullity.”¹³⁰ Not every conspiracy statute requires an overt act,¹³¹ and the act need not be criminal in nature to satisfy the requirement.¹³² Anything from making a phone call to attending a meeting—or even silence—can be an overt act.¹³³ Often, jurors do not need to even agree on what the overt act was.¹³⁴ And an act by any coconspirator is sufficient to fulfill the requirement.¹³⁵ So in “mere presence” cases, the overt act requirement provides no additional protection to the inactive fellow traveler because it is met if someone else acts.¹³⁶ Put simply, the requirement does virtually nothing to constrain conspiracy prosecutions.

In summary, conspiracy’s elements fail to provide meaningful limits on its application. The heart of conspiracy law is the agreement, which requires merely the appearance of concerted action and a period of time, however brief (but not instantaneous), when the defendant could have created or joined a joint scheme. This remarkably loose conception of agreement spills over into every other requirement of conspiracy law.

III. The Structure of Social Movements

Having analyzed the structure of conspiracy law, this Article now turns to the modern structure of social movements before examining how the two intersect. A social movement is a collective campaign that challenges the status quo through displays of “numbers, commitment, unity, and worthiness.”¹³⁷ Social movements play an essential role in the American project of self-governance.¹³⁸ They crystallize issues, foster public discourse, and establish the discursive frames within which we understand the meaning of citizenship and democracy.¹³⁹

Social movements employ a range of tactics, from straightforwardly legal “low-risk” actions like meetings and petitions to “high-risk” actions that may be illegal, such as nonviolent direct action and sometimes even violence.¹⁴⁰ Over the past century, nonviolent direct action¹⁴¹ in particular has become an indispensable social movement tactic within American democracy and abroad, especially when conventional means of change are unavailable.¹⁴² For example, sit-ins or lockdowns—actions taken by a small but dedicated number of activists—demonstrate a movement’s commitment, unity, and worthiness.¹⁴³ Movements around the world have adapted and refined nonviolent direct action, evolving it into a sophisticated political technology essential to modern social movements.¹⁴⁴ As a result, contemporary social movements are often “bifarious,” meaning they include both legal elements and more ambiguous—or even overtly illegal—elements.¹⁴⁵

Two distinctive features of modern social movements are worth examining in further detail. The first is their increasingly decentralized nature, driven by both technological advancements and lessons learned from earlier activist efforts. The second is the importance of strong social ties to the success and sustainability of social movements.

A. The Decentralized Structure of Modern Social Movements

Over the last two decades, social movements have undergone a rapid structural transformation, largely due to the spread of the internet, smartphones, and—above all—social media.¹⁴⁶ These digital tools have made contemporary social movements “more horizontal and egalitarian,” allowing them to operate “more as a network or in peer-to-peer fashion rather than under a strict hierarchy.”¹⁴⁷ In particular, social media has made information transmission nearly frictionless, empowering movements to mobilize more quickly and flexibly than in the past.¹⁴⁸ Where once a series of meetings and in-person introductions were a precondition for a mass rally, today, a Facebook group or a flurry of tweets can do the trick.¹⁴⁹ This is not to say that social media posts alone are enough to organize a movement¹⁵⁰ but rather that social media enables the expansion and connection of existing networks of friends on a scale that most in-person meetings cannot achieve on short notice.¹⁵¹

Social media can also create a “choreography of assembly,” in which online communications effectively script real-world actions.¹⁵² Social media “direct[s] people towards specific protest events, . . . provid[es] participants with suggestions and instructions about how to act, and . . . [constructs] an emotional narration to sustain their coming together in [a] public space.”¹⁵³ In analyzing social movements from Cairo to Istanbul to New York City, scholars have repeatedly found this kind of “choreography of assembly,” in which much of the initial organizing and connecting occurs online, enabling a rapid and seemingly coordinated mass mobilization to follow.¹⁵⁴

One unexpected effect of this frictionless online organizing is that mass events, like rallies and marches, now signal the beginning of a social movement, while in the past, such mass events were the culmination of a long-running movement.¹⁵⁵ As Zeynep Tufekci argues based on her analysis of networked movements around the world:

In contrast to the past, when movements first built up capacity over a long time and only then could stage large protests, today’s movements that are initially organized mostly online generally start the hard work necessary to build a long-term movement after their first big moment in the public spotlight.¹⁵⁶

Although mass mobilization may be easier, rapid online organization can also forestall the creation of “network internalities,” or “the benefits and collective capabilities attained during the process of forming durable networks.”¹⁵⁷ These network internalities are often essential for a movement to sustain itself, resolve disagreements effectively, and adapt to changing adversarial tactics.¹⁵⁸ As a result, although contemporary social movements can more quickly and easily move into the public spotlight than those of the past, they are also more fragile.¹⁵⁹

A further change wrought by social media is that individuals on a movement’s periphery can quickly gain prominence and exercise influence in the movement.¹⁶⁰ Social media features—such as the “mentions column,” which alerts individuals when another user tags them, and trending page, which elevates viral tweets and hashtags, on X (formerly known as Twitter)—offer digital tools that permit individuals to quickly obtain a role in a networked movement.¹⁶¹ Tufekci calls the resulting organizing model an “adhocracy,” in which tasks are “accomplished in an ad hoc manner by whoever shows up and is interested,” rather than by top-down assignment.¹⁶² The rise of these “adhocracies” further weaken modern social movements, as the kind of leadership and decisionmaking structures essential to long-term movement success can remain underdeveloped.¹⁶³ Put simply, digital tools have made modern social movements more participatory, leaderless, and decentralized,¹⁶⁴ which allows them to mobilize faster but also leaves them vulnerable to difficult or unanticipated challenges.¹⁶⁵

B. The Importance of Strong Social Ties to Social Movements

Despite increasing decentralization, contemporary social movements still rely on strong social ties between individuals. In explaining the role of strong social ties, sociologists commonly contrast them with weak ones.¹⁶⁶ Strong ties, such as ties to close friends and family, constitute one’s “inner circle,” while weak ties, such as ties to casual acquaintances and more distant family, make up one’s “outer circle.”¹⁶⁷ Sociologist Damon Centola proposes two visual models for understanding this difference: Weak-tie networks resemble fireworks, in which ties sprout randomly from the individual at the epicenter, while strong-tie networks resemble fishing nets, in which ties are interlocking and redundant.¹⁶⁸ Sociologist Doug McAdam’s groundbreaking study of the 1964 Freedom Rides demonstrates that strong ties with other activists are the best predictor of participation in “high-risk” activism.¹⁶⁹ Although ideology and other factors may have motivated individuals to initially express interest in the Freedom Rides, the intensity of their personal relationships with fellow activists was what motivated their actual participation in the Rides.¹⁷⁰

The importance of strong social ties to effective movement organizing has persisted through the social media revolution.¹⁷¹ Various sociologists note how successful contemporary movements—such as marriage equality, the Arab Spring, and Black Lives Matter—have spread via strong social ties.¹⁷² The “fishing net” structure of strong-tie networks creates social redundancies, and it is this redundant exposure to a new behavior or concept that enables an idea to become a norm.¹⁷³ According to Centola, “[t]he higher the stakes of a decision and the greater the uncertainty, the more ‘proof’ people require—in the form of confirmation from multiple peers—before taking the plunge.”¹⁷⁴ Joining a social movement or adopting its ideas often entails substantial personal risk, and strong social ties create the social reinforcement necessary to accept that risk.¹⁷⁵ In short, even though today’s social movements are largely decentralized—allowing them to mobilize in a seemingly coordinated fashion despite actually being unstructured—they still fundamentally depend on strong bonds between activists to succeed.

IV. Conspiracy’s Threat to Social Movements

Combining the insights of Parts II and III, this Part will explore the ways in which contemporary social movements are especially vulnerable to conspiracy prosecutions and how such prosecutions risk undermining social movements entirely.

A. The Vulnerability of Social Movements to Conspiracy Prosecutions

Social movements are especially vulnerable to the vagaries and excesses of conspiracy law. In particular, the contours of modern conspiracy law have made it all too easy for prosecutors to criminalize mere presence at social movement events and mere expressions of sympathy with a social movement’s aims.

1. Criminalizing Mere Presence

Conspiracy law’s loose definition of agreement—requiring only the appearance of concerted action and an opportunity to create or join a joint scheme¹⁷⁶—permits the criminalization of mere proximity to illegal protest activity. Consider this scenario: Protesters occupy a public park for weeks. Jane, a university student sympathetic to the protest, does not camp out to avoid legal trouble. But she visits her protesting friends, likes their posts on social media, and expresses broad sympathy for their aims. Jane also occasionally joins rallies taking place in the park, though she does so only during the daytime when the park is officially open to the public. Jane also sends her protesting friends class notes whenever they miss lectures, as she does for any absent friend.¹⁷⁷

Jane’s conduct, of course, is hardly wrongful; it is the kind of thoughtful, considerate, and politically attentive activity that sustains a vibrant democracy. Attending occasional rallies, expressing support for protesters, and sharing notes with friends—even when those friends are committing crimes—are protected, permissible activities. Yet under current conspiracy law, Jane could easily be found guilty of conspiracy to commit trespass and nearly any other reasonably foreseeable offense committed by one of her protesting friends. A jury could convict Jane based on her speech at rallies, social media posts, regular visits with her protesting friends, and note-sharing that enabled others to engage in trespassing themselves—all of which create the appearance of concerted action.¹⁷⁸ It would not be hard for a prosecutor to imply a nefarious scheme—“Jane has entered into an agreement with her protesting friends to go to class and take notes for them so that they can continue their unlawful occupation.” This should give us pause. Such a conviction does little more than criminalize friendship and core First Amendment conduct. It also puts Jane in an impossible—and constitutionally troubling—position. She must either avoid associating with the protesters and expressing any sympathy for them or accept the risk of criminal liability, potentially even felony liability in some states.¹⁷⁹

As Jane’s example demonstrates, the risk of criminalizing mere association—a serious issue for conspiracy in general¹⁸⁰—is especially acute for bifarious social movements.¹⁸¹ First, modern social movements generate an abundance of public speech and expression. Activists use social media, hold rallies, distribute literature, and engage in constant communication to build support and coordinate actions. This flood of information creates a wealth of potential evidence for prosecutors to weave into a conspiracy narrative, even when much of the speech being produced is constitutionally protected.¹⁸²

Second, unlike paradigmatic conspiracies, which operate in secret and attempt to conceal their scheming, social movements conduct much of their organizing in the open and strive to project unity and coordination. Movements may thus appear coordinated even when they are actually the product of diffuse and decentralized forces, such as online interactions.¹⁸³

Third, social movements can be messy. In the heat of a protest, some activists might engage in spontaneous property destruction while others engage in planned acts of civil disobedience and still others simply march. The line between those engaging in protected activity and those engaging in unprotected activity can blur, and there is little preventing law enforcement from holding organizers accountable for everything that takes place, whether coordinated or not.¹⁸⁴

Finally, social movements often concern contentious and inflammatory issues in which cool-headedness and restraint are least likely to be exercised.¹⁸⁵ As Geoffrey Stone concluded after examining free speech in wartime: “Again and again, Americans have allowed fear to get the better of them,” and too often “excessively sacrificed the freedom of speech.”¹⁸⁶ Thus, the likelihood of prosecutorial restraint may be at its lowest exactly when the interests of the First Amendment are at their highest.¹⁸⁷

The “SHAC 7” prosecution and conviction illustrates these issues. Stop Huntingdon Animal Cruelty (SHAC) was a global effort to shut down Huntingdon Life Sciences (HLS), a research company that engaged in animal testing.¹⁸⁸ SHAC was a decentralized, grassroots, and bifarious campaign that employed “secondary” protests, in which activists targeted companies affiliated with HLS through both legal and extralegal means by engaging in protests, home demonstrations, and rogue acts of vandalism or property destruction.¹⁸⁹ SHAC-affiliated protests were often brash and confrontational while addressing an emotionally charged topic: the use of animals in research. Much of SHAC’s American activities were loosely coordinated through a website that posted information about the campaign, including bulletins of legal and illegal actions taken by activists against HLS.¹⁹⁰ SHAC brought HLS to the brink of closure several times, and in 2004, federal prosecutors brought charges against six individuals and SHAC itself for, among other things, conspiring to damage an animal enterprise.¹⁹¹ These were the “SHAC 7.”¹⁹² The defendants were ultimately convicted at a trial suffused with political speech, and the Third Circuit upheld their convictions in United States v. Fullmer.¹⁹³

The Third Circuit’s decision in Fullmer is troubling for a number of reasons, chief among them its treatment of mere coordination as conspiracy. The court readily inferred a criminal agreement from the mere fact that many activists had engaged in various actions in the name of a single, unified campaign.¹⁹⁴ The conviction of one defendant, Joshua Harper, is especially revealing of the court’s complacency in allowing mere presence to be criminalized on the basis of flimsy evidence:

Harper coordinated a SHAC campaign in Seattle, . . . gave speeches advocating and explaining electronic civil disobedience[,] . . . visit[ed] . . . a Deloitte and Touche office in Seattle during which it appears he did nothing illegal[,] . . . wrote an editorial in which he endorsed militant action[,] . . . called [a codefendant] to express his surprise and pleasure with SHAC’s successes, and he e-mailed [a codefendant] asking for speakers to travel to Seattle to speak on behalf of the organization and the movement.¹⁹⁵

As the court itself conceded, “Harper’s personal conduct does not cross the line of illegality.”¹⁹⁶ But it upheld his conviction anyway because Harper’s protected activity “provide[d] circumstantial evidence from which a jury could have reasonably inferred that Harper was involved in a conspiracy.”¹⁹⁷ That Harper engaged in speech supportive of a broader, bifarious movement was enough to find him guilty of conspiracy.

2. Criminalizing Mere Sympathy

Conspiracy’s specific intent requirement is meant to be a bulwark against criminalizing mere presence,¹⁹⁸ but in social movement cases, the requirement is all too often satisfied by expressions of mere sympathy. In these cases, activists generally do share a common intent—for example, opposition to a war, belief in animal rights, or support for racial justice. These shared political purposes can transform conspiracy’s specific intent requirement from a shield into a vulnerability. The focus on an activist’s intent invites voluminous evidence on the nature of that intent and highlights the common political vision of all the participants in a social movement, even when they disagree about methods and tactics. Rather than protecting against guilt by association, the intent requirement can facilitate it by emphasizing political kinship over actual criminal intent.

Social movements often involve significant amounts of coordinated speech. This stands in stark contrast to “traditional” conspiracies, like drug-dealing operations or mob enterprises, in which members typically conduct their activities in secret. In these traditional conspiracies, incriminating communications may be coded, shared only in person, or quickly destroyed, making it difficult to prove a member’s specific intent to join the conspiracy through anything but ambiguous circumstantial evidence.¹⁹⁹ Members of social movements, on the other hand, tend to engage in significant and public speech, like chanting at rallies, posting on social media platforms, and engaging in other forms of open expression. In other words, social movement cases are unique because of the sheer volume of speech-related evidence.²⁰⁰ This abundance of evidence can have a cumulative effect on a jury.²⁰¹ When presented with numerous statements expressing sympathy for a cause, jurors may mistakenly conclude that an individual specifically intended for even the movement’s most extreme actions to occur, rather than recognizing these statements as expressions of general support or ideological alignment.²⁰²

This problem can be exacerbated by the tone of activist speech. Social movements often employ overheated rhetoric that can easily be taken more literally or seriously than intended. For example, the Third Circuit held that “[o]ne of the more incriminating pieces of evidence against”²⁰³ one of the SHAC defendants was a video of the defendant leading a chant at a protest target’s house in which she shouted, “[W]hat goes around comes around,” and the group replied, “[B]urn his house to the ground.”²⁰⁴ Or, in considering Tom Hayden’s conspiracy conviction in the Trial of the Chicago 7, the Seventh Circuit found that Hayden’s famous speech—“if we are going to be disrupted, and violated, let this whole stinking city be disrupted and violated”—was sufficient evidence to sustain his conviction.²⁰⁵ Impassioned speeches like these may seem more menacing when presented in a sterile legal environment, divorced from their original context.²⁰⁶ Social media makes matters worse. Research has identified an “online disinhibition effect,” in which individuals tend to express themselves more aggressively online than in person.²⁰⁷ Activists may post hundreds or thousands of times over the course of a social movement campaign, allowing prosecutors to cherry-pick the most provocative statements to present to the jury.

Finally, research has shown that juries often resort to stereotypes or other familiar narratives to make sense of defendants in high-profile cases and frequently allow pretrial publicity to influence their judgments despite judicial instructions to the contrary.²⁰⁸ Given the cultural salience of many modern social movements—such as “antifa”²⁰⁹ or “Black Lives Matter”²¹⁰ or “free Palestine”²¹¹—and the high probability of pretrial publicity for social movement cases, this kind of stereotyping may be especially likely.

Taken together, these features of social movement cases—an immense volume of speech, an overheated tone to that speech, and the stereotyping of activist-defendants—make it all too easy for juries to misconstrue an activist’s mere sympathy or ideological alignment with a social movement’s aims as specific intent to engage in criminal activity.

The prosecution of the “Boston 5”—five Vietnam War protesters, including the famous pediatrician Dr. Benjamin Spock—in United States v. Spock illustrates how mere sympathy can be recast as specific intent. Spock emerged out of the 1960s anti-war movement. With protests spreading across the country, the Department of Justice chose to make an example of especially prominent anti-war leaders.²¹² The defendants were chosen, as one of the lead prosecutors frankly admitted, precisely because of the great volume of speech they had engaged in: “We wouldn’t have indicted them except for the fact there was so much evidence available on film.”²¹³ The five defendants were charged with conspiracy to counsel, aid, and abet draft resistance.²¹⁴ But the Boston 5 shared little more than a fierce opposition to the Vietnam War and the occasional rally stage.²¹⁵ In fact, when the five met for the first time after the indictment, one of their attorneys said, “the first thing he felt he could do for these conspirators was to introduce them to each other.”²¹⁶

The indictment listed a variety of speech acts as overt acts, including distributing a statement titled, “A Call to Resist Illegitimate Authority”; delivering various speeches and press conferences; and turning in draft cards to the Department of Justice.²¹⁷ The nearly monthlong trial included numerous videos of protests and speeches.²¹⁸ Jessica Mitford, who sat through the trial, said it amounted to “[a] miscellany of public utterances, public appearances, sermons, press conferences, [and] printed declarations of beliefs.”²¹⁹ Curiously absent was any discussion of a specific intent by the Boston 5 to agree to commit a crime.²²⁰ Instead, the prosecution relied on ideological sympathy as circumstantial evidence. In a particularly striking example, the prosecution noted that one defendant had applauded when another defendant spoke.²²¹ “Was your applause merely perfunctory politeness to [the defendant] or did you applaud in agreement with the position he was taking, and in advocacy of the same position?” the prosecutor asked.²²² Elsewhere, the prosecutor claimed that clapping “like mad” during a speech could make one a coconspirator while “sit[ting] glum[ly]” would not.²²³ Four of the five defendants in Spock were convicted, though the First Circuit later reversed all their convictions on a technicality and two on sufficiency of the evidence grounds.²²⁴

Spock demonstrates that the volume and vehemence of speech can substitute for evidence of specific intent.²²⁵ Prosecutors went after Dr. Spock and his codefendants precisely because they had engaged in significant amounts of public speech, and the trial court permitted prosecutors to use that speech—and the defendants’ ideological alignment—against them. It is also worth noting that Spock and Fullmer (the SHAC 7 case) predate the social media revolution that has generated an abundance of public speech, escalated the intensity of that speech, and enabled activists to project an appearance of organization onto a disorganized group.²²⁶ The defects identified in Spock and Fullmer are thus even more acute today.

3. Metastatic Rules of Evidence

“The metastatic rules of ordinary conspiracy” facilitate the criminalization of mere presence and sympathy by permitting prosecutors to introduce voluminous speech evidence that often provides a one-sided and misleading portrayal of the defendant’s actions and expressions.²²⁷

First and foremost, conspiracy permits the admission of protected speech as probative of unprotected speech. For example, the prosecution in Spock played footage of rallies, speeches, and press conferences and shared the defendants’ protected written statements,²²⁸ while the prosecution in Fullmer introduced evidence from SHAC’s public website, descriptions of protests, and press releases.²²⁹ Other social movement prosecutions have similarly inundated the jury with protected political speech.²³⁰ The prosecution in these cases never alleged that any of these statements were themselves criminal—indeed, most were clearly protected as core First Amendment speech. Nevertheless, the prosecution in each case could bombard the jury with protected speech because such speech is relevant to circumstantially prove agreement and intent.²³¹ The only prophylactic against misusing speech is a limiting instruction from the judge, but research has shown that limiting instructions are “ineffective and have even been associated with a paradoxical increase in the targeted behavior.”²³²

Second, conspiracy relaxes the rules for the admissibility of hearsay.²³³ A court—rather than a jury—can find the existence of a conspiracy by a preponderance of the evidence, rendering all coconspirator statements admissible against the defendant.²³⁴ This liberal admission of coconspirator hearsay is especially problematic in social movement cases, where prosecutors often argue for an extremely broad definition of who qualifies as a coconspirator. In the Spock trial, for example, the prosecution claimed that all 28,000 signers of a “Call to Resist Illegitimate Authority” were coconspirators.²³⁵ If vindicated in court, any of their statements would have been admissible against the defendants.

Finally, courts permit prosecutors to introduce a wide range of potentially prejudicial material against defendants, while simultaneously restricting defendants from presenting contextual evidence that might explain their actions or motivations. In Spock, the prosecution was able to admit significant evidence of abrasive and even shocking speech, but the defendants were not allowed to admit evidence concerning the legality of the Vietnam War—the very issue that had produced their speech.²³⁶ Likewise, in Fullmer, the court admitted the defendants’ inflammatory speech, including chants and online descriptions of protests, but excluded the evidence of animal cruelty that had spurred the protests in the first place.²³⁷

Other conspiracy prosecutions beyond those in Spock and Fullmer featured similar evidentiary asymmetries. For instance, in a conspiracy prosecution of a supporter of Puerto Rican independence, the court admitted evidence of the defendant’s political activities but did not permit the defendant to contest the lawfulness of American authority over Puerto Rico.²³⁸ In the conspiracy prosecution of an anti-abortion activist, the court admitted the defendant’s pro-life social media posts and other statements but did not permit the defendant to testify about the allegedly cruel practices occurring inside the abortion facility she locked down.²³⁹ And in the conspiracy prosecution of an animal rights activist, the court admitted speech by the activist and his alleged coconspirators but excluded evidence of animal cruelty.²⁴⁰

Strictly speaking, the legality of the Vietnam War, American control of Puerto Rico, abortion, or animal mistreatment were not directly relevant to whether the actions of any of these defendants were lawful, and such evidence could be highly inflammatory in its own right. But research has shown that juries often render their decisions through a story-based model of decisionmaking, deciding guilt or innocence based on how the defendant’s actions fit into a broader narrative of the alleged crime.²⁴¹ By admitting evidence of provocative protests by social-movement defendants but excluding evidence concerning the causes of those protests, courts create an evidentiary asymmetry that severely disadvantages activist defendants. Indeed, evidentiary asymmetry may be one reason why prosecutors increasingly select conspiracy as the charge of choice in social movement cases.²⁴²

B. Conspiracy’s Threat to Social Movements

Conspiracy law poses a unique threat to social movements by targeting precisely what makes them work: strong social ties and public speech. Central to understanding conspiracy’s threat is the concept of chilling effects. Chilling occurs when individuals are deterred from engaging in protected conduct by regulations aimed at unprotected conduct.²⁴³ The conventional account of chilling effects posits that they result in self-censorship, as individuals “exercise[] a kind of self-restraint” to avoid coming under the purview of a vague law.²⁴⁴

Subsequent scholarship has expanded our understanding of chilling effects in two key ways. First, chilling can result from “increased risk of future privacy-related harms”—not just government sanction—as individuals fear the release of sensitive or embarrassing personal information.²⁴⁵ More recently, Jonathon Penney has drawn on social science research to argue that chilling also occurs through “social compliance”: “[C]ontexts of ambiguity—such as ambiguity in the law or a circumstance where a person is aware they may be monitored by the government[,]” can give rise to chilling effects. “[I]n such uncertainty . . . people tend to act the way they believe others would act in the same circumstance, that is, they follow the norm.”²⁴⁶ Highly publicized government surveillance produces a social compliance effect, deterring people from engaging in protected but potentially controversial conduct, and this effect can persist for an extended period of time.²⁴⁷ Put simply, high-profile government crackdowns—like a conspiracy prosecution—can produce not only self-censorship but also, more problematically, social compliance, in which individuals change their behavior to conform to what they believe to be the majority view.²⁴⁸

Conspiracy prosecutions chill the strong social ties essential to the success of modern social movements. Strong social ties—the kind that exists between an “inner circle” of close friends—are crucial for effective social movements, especially ones that engage in highly communicative “high-risk” actions like nonviolent direct action.²⁴⁹ But conspiracy directly criminalizes those social ties. Consider again the example of Jane and her park-occupying friends.²⁵⁰ If Jane or the park occupants are charged with conspiracy to trespass, the state effectively criminalizes their social bonds. Every message sent between the friends—even private ones not directly related to the protest—becomes relevant and admissible in court to prove the existence of a conspiracy. Every social media post and “like,” as well as every interaction between the friends, can be used to imply a hidden, nefarious scheme. And the most extreme posts of one alleged coconspirator would be admissible to establish the culpability of all others.²⁵¹ From a social movement perspective, this form of criminalization is highly problematic. Because one friend’s expression can be used against another, friendship itself becomes a liability. If the individuals were convicted, they would likely be subject to no-contact orders that would severely hinder their ability to organize.²⁵²

To make matters worse, conspiracy is a more unpredictable and sprawling offense than a substantive crime like trespass. Jane, for example, could avoid a trespass charge by adhering to park rules, such as leaving at dusk, while maintaining contact with and general support for her friends.²⁵³ But conspiracy potentially criminalizes these behaviors by making them evidence of an implied agreement. Worse still, Pinkerton liability means that Jane could be on the hook for the crimes of more radical activists—for example, if some park occupants overturn police barricades, assault police officers, or engage in other reasonably foreseeable crimes in furtherance of the occupation. The possibility of such broad liability is likely to chill Jane’s association with her friends. Concerned that her connections to the protest movement might be implicated in a conspiracy prosecution, Jane may self-censor on social media, avoid visiting friends in the park, and refrain from attending protests altogether, despite her underlying support for the movement. These chilling effects weaken the very foundations of a social movement and are cause for concern in a society committed to democratic self-governance.

Conspiracy prosecutions also undermine social movements by eroding social trust and destabilizing group identities. In his article defending conspiracy law, Neal Katyal argues that conspiracy law is an extremely effective tool for combatting group enterprises.²⁵⁴ Among other things, he argues that conspiracy promotes information extraction by encouraging flipping²⁵⁵ and encourages the adoption of inefficient practices to avoid prosecution, like mutual monitoring, “that generate inefficiencies, stymie group identity, and sow distrust within the group.”²⁵⁶ But the very features that make conspiracy law so effective against corrosive criminal organizations like gangs and mobs also render it a powerful instrument for undermining social movements that promote democratic self-government. The lurking possibility that new social movement members might be informants or could be induced to flip on their allies inevitably fosters a culture of suspicion and distrust, ultimately fraying the strong social ties that are crucial to a movement’s success and sustainability.

Conspiracy prosecutions not only chill association but also threaten to stifle social movement speech. In nearly every conspiracy prosecution targeting social movements, speech has played a central role as circumstantial evidence of agreement and intent.²⁵⁷ Even when speech itself is constitutionally protected, research shows that its proximity to conduct criminalized by the government makes it particularly vulnerable to chilling effects.²⁵⁸

The animal rights movement provides an instructive case study on how the threat of conspiracy can unravel a movement. The modern animal rights movement is comparatively young, with its origins in the mid-1970s.²⁵⁹ For its first few decades, the movement was driven by grassroots energy, including leaflet-and-picket protests and concerted campaigns to shut down animal-abusing facilities.²⁶⁰ The movement became bifarious in nature, combining traditional protest activities with occasional criminal acts.²⁶¹ The SHAC campaign, which arrived in the United States sometime in 2000 or 2001, typified this bifarious approach to social change.²⁶² The movement’s success in threatening the bottom line of the animal-testing industry in part caused the FBI to take notice and crack down on animal rights activists in what some have called the “Green Scare.”²⁶³ Central to this crackdown was the conspiracy prosecution of the SHAC 7, which had a profound impact on the animal rights movement, undermining it in precisely the manner described earlier in this Section. The specter of prosecution caused the grassroots animal rights movement to stall and struggle to attract new members. As longtime activists recalled:

People would show up to their first protest ever . . . and that weekend the FBI would knock on their door, asking for the names of fellow protesters . . . . [C]onfronted with such zealous opposition, the U.S animal rights movement and its benefactors pivoted away from grassroots activism toward an institutional, “within the system” approach.²⁶⁴

The chilling effect extended beyond just deterring new recruits. Some established members of the animal rights movement grew wary of one another, suspecting that newcomers might be informants or that longstanding allies might “flip” and inform on them.²⁶⁵ The successful prosecution of SHAC for essentially running a website instilled a pervasive fear that the government could criminalize virtually any activist, even if they themselves had not participated in illegal direct action.²⁶⁶

The animal rights movement is not an isolated example.²⁶⁷ Conspiracy, more than any other kind of offense, can be weaponized against a social movement as a whole and have profoundly anti-democratic consequences. It can drive moderates away from a movement, leaving only hardened extremists, or shift a movement’s gravity away from grassroots activism and toward elite institutions and nonprofits.²⁶⁸ These risks are especially acute for modern movements, which can mobilize en masse with relative ease but often lack the developed movement infrastructure needed to subsist once they emerge onto the national stage.²⁶⁹ This fragility, combined with the threat posed by conspiracy liability, puts modern social movements at unusually great risk.

V. The Inadequacy of Current First Amendment Protections

Current doctrinal safeguards are insufficient to protect contemporary social movements from the threat posed by conspiracy law. That it is often easier for prosecutors to obtain a conspiracy conviction than a conviction for the underlying substantive offense in social movement cases is alarming,²⁷⁰ and that prosecutors actively prefer using conspiracy against activists rather than ordinary substantive offenses is of equal concern. This Article has already addressed how the usual safeguards, like specific intent and appellate review, are insufficient to adequately protect activists’ First Amendment rights.²⁷¹ Recognizing social movements’ First Amendment importance, courts have also developed additional doctrinal safeguards specifically for prosecutions of social movements. But these too are insufficient.

The First Amendment unequivocally protects the constitutive features of social movements: speech, association, and petitioning. Beyond these components, social movements themselves—as collective campaigns to shape public opinion²⁷²—are at the heart of what the First Amendment seeks to protect.²⁷³ The Supreme Court has acknowledged that a primary purpose of the First Amendment is to protect the conditions of self-government.²⁷⁴ This protection necessarily extends to social movements, which are self-government in action: Citizens mobilizing en masse to frame issues, persuade the public, and pursue their vision of a just social order. This Part argues that current First Amendment doctrine—in the context of conspiracy prosecutions in particular—inadequately protects both individual speech acts and the broader conditions that allow social movements to thrive.

It is well established that the expressive act of joining a conspiracy receives no constitutional protection.²⁷⁵ Such speech falls into the “[s]peech integral to criminal conduct” exception to the First Amendment.²⁷⁶ But whether any particular expression falls into this exception can be a fraught question. For example, the prosecution in Spock argued that signing the Call made one a conspirator,²⁷⁷ but this notion was later rejected by the First Circuit.²⁷⁸ Or, imagine one of the SHAC defendants posting online: “Let’s shut down Huntingdon Life Sciences!” That post could qualify as direct evidence of a criminal agreement (and thus covered by the speech integral to criminal conduct exception) or a court could find it to be merely circumstantial evidence of an agreement (and thus uncovered by the exception). In any case, the distinction is more formal than consequential. Both forms of expression are admissible to the jury, and appellate courts will defer to the jury’s interpretations of such ambiguous statements.²⁷⁹

The other speech acts relevant to a conspiracy case are those that can be used as circumstantial evidence of a conspiratorial agreement. For these speech acts, courts have occasionally deployed a muddled rule known as “strictissimi juris.”²⁸⁰ Literally, “according to the strictest law,” strictissimi juris requires a court to strictly construe facts when it is uncertain whether a defendant’s conduct is protected by the First Amendment.²⁸¹ The rule originated in two Supreme Court cases, Noto v. United States and Scales v. United States, which both held that membership in a bifarious organization like the Communist Party “must be judged strictissimi juris” to avoid guilt by association.²⁸² Or, as the First Circuit eloquently put it, strictissimi juris applies “[w]hen the alleged agreement is both bifarious and political within the shadow of the First Amendment.”²⁸³ Though sometimes applied at the trial court level,²⁸⁴ strictissimi juris is most often viewed as an appellate rule for reviewing the sufficiency of the evidence.²⁸⁵

That said, lower courts have interpreted strictissimi juris in various, sometimes contradictory ways.²⁸⁶ Some courts have interpreted the rule as imposing a higher burden for sufficiency of the evidence or requiring courts to exercise heightened skepticism of certain prosecutions.²⁸⁷ While this approach may sound promising in theory, in practice, courts that claim to take this approach often just pay lip service to the First Amendment and strictissimi juris before deferring to the jury verdict as usual.²⁸⁸ At best, this approach reinforces the need for individualized evidence against each defendant—a safeguard already built into conspiracy law.²⁸⁹

In Spock, the First Circuit gave the strictissimi juris rule more bite, interpreting it as a restriction on the use of circumstantial evidence,²⁹⁰ but no other court has followed their lead.²⁹¹ The Spock court held that, to sustain a conspiracy conviction implicating First Amendment concerns, the prosecution must provide proof of the defendant’s specific intent in one of three ways:

by the individual defendant’s prior or subsequent unambiguous statements; by the individual defendant’s subsequent commission of the very illegal act contemplated by the agreement; or by the individual defendant’s subsequent legal act if that act is “clearly undertaken for the specific purpose of rendering effective the later illegal activity which is advocated.”²⁹²

While more protective, this formulation of strictissimi juris rule raises other concerns. The first and third prongs—requiring an “unambiguous” statement or an act “clearly undertaken for [a] specific purpose”—are overly vague requirements that do little to clarify the already nebulous demands of conspiracy law. And the second prong oddly incorporates the commission of the underlying substantive offense into the conspiracy analysis, despite conspiracy being traditionally viewed as a “distinct evil” separate from the substantive crime.²⁹³ The approach is also unsatisfactory because it can lead to unexpected and even unjust outcomes.²⁹⁴ For example, in applying this more rigorous strictissimi juris rule, the First Circuit reversed Dr. Spock’s conviction for insufficient evidence but upheld the convictions of two codefendants, even though Dr. Spock was a more central figure in the alleged conspiracy and there was no principled distinction between his activities and those of his two codefendants.²⁹⁵ This version of strictissimi juris may be more forceful but only at the expense of clarity and consistency.

Putting these concerns aside, the main reason strictissimi juris fails as a safeguard—both for individual speech acts and for protecting the conditions for social movements more generally—is that it is too vague, too little, and too late. Even in its strongest form, the rule is nebulous and difficult to apply in a consistent manner.²⁹⁶ It continues to allow the great flood of protected speech that accompanies most contemporary social movement prosecutions. So long as that speech is admissible, activists will be chilled and juries will be invited to use unpopular but protected expressions against them. Most importantly, the rule does not reduce—and may even amplify—the uncertainty inherent in conspiracy prosecutions, and it is this uncertainty that chills speech and association.²⁹⁷ Despite its nobler intentions, the strictissimi juris rule is just another vague legal test, and it is one that comes into play at the end, rather than the beginning, of a prosecution. By that point, the damage is already done.²⁹⁸ Put simply, the doctrine of strictissimi juris accurately diagnoses the threat conspiracy poses to First Amendment activities but falls woefully short as a solution.

VI. Effectively Abolishing Conspiracy for Social Movements

The only way to adequately protect modern social movements from the antidemocratic threat of overly broad conspiracy prosecutions is to effectively abolish conspiracy for social movements.²⁹⁹ Anything less leaves social movements exposed to having their social ties targeted and their public expressions chilled. While achieving this goal presents significant challenges, this Part demonstrates how we can nonetheless make meaningful progress while balancing the importance of social movements against public safety concerns. In particular, this Part proposes effectively abolishing conspiracy charges for social movements by prohibiting certain public, expressive, and nonviolent offenses—like trespass, unlawful assembly, and obstruction—from being used as conspiracy predicates. Because activists are disproportionately likely to commit offenses like these, putting them beyond the reach of conspiracy law would go a long way toward protecting social movements while allowing prosecutions of more dangerous conspiracies. Though fashioned to safeguard social movements, this solution is necessarily broader in scope, removing these crimes as eligible conspiracy predicates for everyone, not just activists. This approach would not unduly sacrifice public safety or order, as harmful conduct could still be policed by charging the target with the substantive crime itself, accomplice liability, or attempt—each sufficient to address public safety concerns without the negative externalities of conspiracy.

To begin, it is worth frankly acknowledging the two competing values at stake: protecting democratic self-governance, which is enabled by social movements, and protecting safety, order, and the rule of law, which is enabled by prosecuting criminal agreements. Adjudicating tradeoffs like these is at the heart of much of our First Amendment jurisprudence, which balances the values of free expression against the importance of maintaining social order.³⁰⁰

But the tiered structure of current First Amendment law fails to adequately address this tradeoff in the context of conspiracy prosecutions of social movements.³⁰¹ First Amendment doctrine takes a categorical approach: Once an expression has been deemed unprotected—for example, because it is integral to criminal conduct—virtually any criminal regulation is permitted.³⁰² The entirety of the First Amendment inquiry focuses on whether certain activity can be criminalized, neglecting the crucial question of how that criminalization occurs.³⁰³ As this Article has shown, the method of criminalization can be as significant as the fact of criminalization itself.

For this reason, I propose limiting which offenses can be predicates for a conspiracy charge. Offenses that are public, nonviolent, and disproportionately likely to be done openly by activists should be beyond the reach of conspiracy law. Such offenses include, at a minimum, trespass, disorderly conduct, unlawful assembly, obstruction of justice, failure to disperse, and speech-based crimes like counseling draft evasion or inciting a riot.³⁰⁴ While this approach errs on the side of over-protecting First Amendment interests by making these offenses unavailable as conspiracy predicates for everyone, it also offers significant advantages.³⁰⁵

First, this solution is straightforward, predictable, easily administered by courts, and readily understandable by activists and prosecutors alike. While the solution is over-inclusive, it avoids the thorny issues that would be raised by a narrower approach that requires courts to decide whether a particular group counts as a “social movement” before shielding it from conspiracy.³⁰⁶ Instead, this solution reverse engineers protections for social movements by exempting certain crimes that are disproportionately committed by movement activists.

This clarity also makes the proposed solution more effective than middle-ground approaches that merely reform conspiracy’s elements.³⁰⁷ For example, drawing on contract law, Laurent Sacharoff persuasively argues that conspiracy law should define the agreement as an exchange of promises.³⁰⁸ While Sacharoff correctly identifies the agreement element as conspiracy’s fatal flaw and his solution mitigates many of the dangers identified in this Article, it does not eliminate them outright. Prosecutors can still circumstantially attempt to prove an exchange of promises using activists’ overheated rhetoric, and the mere possibility of such charges would still chill movement activity.³⁰⁹ Any solution making conspiracy law clearer and more demanding is welcome, but abolishing conspiracy for public, low-level offenses provides the cleanest and strongest protection for modern social movements.

Second, this solution properly balances the public interest in robust social movements with the public interest in maintaining safety and order. As this proposal recognizes, the state has an overriding interest in preventing violence.³¹⁰ Not only is the harm of violent crime more severe, but political violence is also at odds with genuine self-governance because it seeks change through coercion rather than public appeal.³¹¹ At the very least, the line between violence and nonviolence is socially and legally salient, and a plausible reform should account for this distinction.³¹² As the Supreme Court has repeatedly held, “[t]he First Amendment does not protect violence.”³¹³ By putting only publicly expressive, nonviolent crimes beyond the reach of conspiracy, my proposal accommodates the deeply engrained interest in disallowing violence. And to the degree that expressive, nonviolent crimes like trespass pose a genuine danger, the state still retains the ability to prevent and prosecute such crimes as individual substantive offenses—just not as conspiracy offenses.³¹⁴

Moreover, the criminalization of conspiracy is primarily justified by the unique dangers posed by secretive group crimes.³¹⁵ Social movements, however, often organize openly, and their illegal acts, like sit-ins or road obstructions, are often highly publicized—and intentionally so, as their very goal is to win public attention. The great virtue of my proposal, then, is that it intervenes precisely at the nexus where the interests justifying prosecution are at their lowest and the concerns of the First Amendment are at their highest.

Additionally, one welcome side effect of removing expressive, nonviolent offenses from the purview of conspiracy is that it channels activism toward the most desirable and effective forms of protest. As movement sociologists have documented, nonviolent social movements tend to be more successful than their violent counterparts in achieving desired reforms and ensuring their durability.³¹⁶ The finding is not that law violation is at odds with social reform—often the opposite is the case—but rather that certain kinds of law violations, namely nonviolent ones, are especially effective.³¹⁷ While the primary aim of my proposal is not to prescribe strategies for activists, it is an advantage that the proposal promotes forms of activism that are both effective and aligned with the principles of democratic self-governance.³¹⁸

By way of example, consider the crime of trespass, the paradigmatic example of an offense that should be beyond the reach of conspiracy under my proposal. Trespass is nonviolent and typically done openly by activists, allowing for swift detection and prosecution as a standalone offense if necessary. If police want to remove activists for trespassing—whether it be from a coal railroad,³¹⁹ a factory farm,³²⁰ or the nation’s Capitol³²¹—they are perfectly capable of doing so, and prosecutors can bring individual charges for trespass. What prosecutors cannot do under my proposal is charge the activists and their affiliates with conspiracy to trespass because such a charge could chill protected speech, sweep in sympathetic supporters who did not personally trespass, and fray the social ties on which the movement relies. The same analysis applies to other protest- and speech-related crimes.³²²

This approach of limiting conspiracy-eligible crimes finds some precedent in existing case law. The Supreme Court has repeatedly created “buffer zones” to guard against potential chilling effects on speech.³²³ Courts also “review[] First Amendment vagueness and overbreadth claims more aggressively in the criminal context than in the civil context.”³²⁴ These practices reflect a constitutional preference for over-protecting First Amendment interests when faced with potentially chilling criminal statutes. Excluding certain crimes as conspiracy predicates may provide the overprotection needed to guard social movement organizing and speech from the threat currently posed by conspiracy law.

One counterargument warrants attention. Could restricting conspiracy liability actually harm social movements by reducing opportunities for civil disobedience or voluntary prosecution? As scholars (including myself) have argued elsewhere, when institutional channels for change are blocked, movements sometimes strategically use criminal trials as platforms for reform, essentially leveraging the prosecution to present their case to the public.³²⁵ By shrinking the state’s ability to punish certain offenses, my proposal arguably threatens this important activist tactic. But my proposal eliminates only conspiracy liability, not prosecution itself. Activists who trespass, for example, can still face prosecution for that underlying offense and use the trial to challenge an injustice; they just will not face a conspiracy prosecution in particular. This approach offers two advantages. First, limiting conspiracy charges in this manner makes potential liability more predictable, enabling activists to make more deliberate choices about their direct actions. Second, prosecutions for substantive offenses better serve movements’ communicative goals than prosecutions for conspiracy. Activists rarely seek to highlight state suppression of collective organizing (the focus of conspiracy); rather, they aim to spotlight the state’s criminalization of substantive conduct.³²⁶ Channeling prosecution toward substantive offenses may therefore enhance, rather than hinder, activists’ abilities to effectively engage in civil disobedience or voluntary prosecution.

Limiting the reach of conspiracy is just one possible solution to the problem identified in this Article. Other potential reforms—like allowing for early dismissals of conspiracy charges in social movement cases,³²⁷ entirely excluding core First Amendment speech in social movement trials,³²⁸ or tightening the requirements for conspiracy itself³²⁹—are just a few alternatives that would also go a long way to mitigating the worst excesses of conspiracy law. The primary goal of this Article is not to prescribe a single solution but rather to identify a pressing and serious problem and to inspire doctrinal and policy innovation on this issue.

Conclusion

This Article has argued that conspiracy poses a unique threat to social movements. The looseness of conspiracy doctrine—requiring nothing more than the appearance of concerted action and an opportunity to create or join a joint scheme—makes it dangerously easy for prosecutors to criminalize mere proximity to protest activity and mere sympathy with movement aims. This danger looms especially large for today’s social movements. Though these movements can mobilize more rapidly than ever, they are also more vulnerable to government repression. The ease of online organizing means that modern social movements are less likely to have developed the decision-making structures and internal competencies necessary to withstand a government crackdown. The result is movements that appear large, powerful, and coordinated, but are actually more fragile than their historical counterparts. Conspiracy, which targets the social ties that make movements work, is thus a greater threat than ever before.

This threat is especially concerning because social movements have an important role to play in protecting democratic self-governance. Today, Americans’ trust in institutions is plummeting, social bonds are fraying, and political polarization is reaching historic levels. Social movements are an important antidote to these ills. They are not just mechanisms for achieving specific reforms; they are also spaces where citizens forge connections across difference, develop civic capabilities, and practice democratic citizenship. Yet it is precisely when social movements are most vital that they become most vulnerable to suppression. The same forces that make social movements essential—growing polarization, institutional distrust, and social atomization—also make their disruptive tactics and demands for change appear more threatening. Conspiracy law provides prosecutors with an especially potent weapon for neutralizing these perceived threats. The solution this Article proposes—effectively abolishing conspiracy for social movements—is thus not just about protecting activists; it is also about preserving democracy’s capacity for renewal and reform.

* Litigation Fellow, Animal Activist Legal Defense Project at the University of Denver’s Sturm College of Law. I am grateful to Justin Marceau, Laurent Sacharoff, and Wayne Hsiung for their helpful feedback on earlier drafts of this Article. This Article was also improved by thoughtful comments from Nancy Leong, Alan Chen, Sam Kamin, Amanda Savage, Elizabeth Jordan, Rebecca Aviel, and other participants of Denver University’s faculty workshop sponsored by the Animal Law and Constitutional Rights & Remedies Programs.