A man holds a large Q sign, referencing the Qanon conspiracy theory, at a rally for President Donald Trump on August 2nd, 2018, in Wilkes Barre, Pennsylvania. (Photo: Rick Loomis/Getty Images)

For the last half century, the outer limit of free speech in America has been defined by violence. In Brandenburg v. Ohio (1969)—involving an Ohio Ku Klux Klan leader who was arrested following a hate-filled public speech that police saw as advocating for crime—the United States Supreme Court ruled in a majority opinion that the government cannot restrict or punish inflammatory speech unless it can prove that such speech is both "directed at inciting or producing imminent lawless action" and "likely to incite or produce such action."

The ruling established a "Brandenburg test" of intent, likelihood, and imminence to replace the "clear and present danger" test of Schenck v. United States (1919), the ruling best known for giving America "shouting fire in a theater" as an aphorism describing actions that have a tendency to cause panic and "create a clear and present danger" through sedition or lawlessness. While "mere advocacy" like that exercised by the Ohio KKK leader may be protected by the First Amendment, according to Brandenburg, incitement that's both intended and likely to produce imminent violence is not.

Now, it looks as though the Court might see another chance to refine the outer edges of free speech in the U.S.—but instead of shouting fire in a crowded theater, the nation's highest court may end up evaluating the protections for yelling "Deep State!" on Facebook. According to a Federal Bureau of Investigation intelligence bulletin, the U.S. government officially sees fringe conspiracy theories as a substantial domestic terror threat insofar as "anti-government, identity-based, and fringe political conspiracy theories [are] very likely encourage the targeting of specific people, places and organizations" for potential violence.

While an intelligence bulletin isn't the same as an official "domestic terrorist" designation, it's still a revealing document. Compiled by the FBI Phoenix Field Office on May 30th and obtained by Yahoo News, the "high confidence" assessment was based on intel from open-source information, court documents, a decade of FBI and other law enforcement investigations, and "human sources with varying degrees of access and corroboration."

More specifically, the bulletin cites several incidents involving suspects inspired by the QAnon and Pizzagate conspiracy theories, which involve, respectively, a covert campaign led by an anonymous government official named Q against a Deep State of unelected elites who secretly control the U.S. government, and a cabal of elite liberal and Democratic political figures who abuse children in a Washington, D.C., pizza parlor. Both conspiracies have spread since President Donald Trump took office. Both target liberals, Democrats, and elected officials perceived as part of the "global elite." And, notably, both see Trump as their savior.

Even worse, the bulletin seemed prescient: Days after Yahoo News published the document, a self-identified white nationalist killed 20 people at a Walmart in El Paso, Texas. Hours before the shooting, the killer published a manifesto overflowing with white supremacist conspiracy theories about a "Hispanic invasion of Texas," according to the New York Times, invoking the same paranoia about a "white extinction" caused by mass immigration and multiculturalism that animated the perpetrator of the New Zealand mosque attacks of March of 2019. As of Sunday, federal authorities are treating the case as a domestic terrorist incident.

While their ideological contours are different, these conspiracy theories seems to be their own brand of internet-fueled extremism, distinct from other more traditional forms. "The FBI considered the alternative hypothesis that domestic extremists likely turn to violence only as a result of any underlying extremist ideology (such as militia extremism or white racially motivated violent extremism), whereas conspiracy beliefs held by such extremists do not play a role in their mobilization to violence," the bulletin states. "The FBI deemed this alternative to be less likely because these conspiracy beliefs have motivated, at least in part, several high profile violent acts, or have influenced their perpetrators to the extent that they attributed their actions to their conspiratorial beliefs before or after their arrests."

The FBI's specific inclusion of QAnon and Pizzagate appears to, in some ways, foist blame on those in the media ecosystem who happen to propagate those theories—and that includes Trump, even though the president is only mentioned in the FBI report by name in reference to his place in QAnon hagiography. Since 2017, Trump has repeatedly shared tweets and content from QAnon supporters, amplifying those conspiracies to his mass audience; earlier this month, Trump even invited a cadre of far-right online personalities who traffic in such conspiracies to discuss social media and politics at the White House; just one day before the Yahoo News report dropped, Trump used his preferred bully pulpit of Twitter to elevate two QAnon conspiracy theorists.

While the FBI doesn't explicitly point to Trump and his ilk for fostering this "domestic extremism," the connection is unnerving. As I wrote in the aftermath of the October of 2018 Tree of Life synagogue massacre in Pennsylvania—an incident that the FBI explicitly cited in its intelligence bulletin—political scientists tend refer to this phenomenon as "stochastic terrorism," the use of mass communication to "incite random actors to carry out violent or terrorist acts that are statistically predictable but individually unpredictable." That Trump is the hero in the QAnon theory—and that, thanks to his stamp of approval, the conspiracy whispers at his rallies and in the campaigns of fringe candidates—it's difficult to see this as unpredictable.

The American legal community seems fairly certain that conspiracy-mongering isn't protected under the First Amendment: In an amicus brief filed in a defamation case against InfoWars host Alex Jones, four legal scholars wrote that "False speech does not serve the public interest the way that true speech does ... and indeed, there is no constitutional value in false statements of fact."

But while the FBI is on the lookout for conspiracy-fueled extremists, it's not totally clear if conspiracy theories are speech that the government can actively prohibit under the Brandenburg test. Even if proof existed of intent to incite, the whole concept of stochastic terrorism suggests that imminence and likelihood are necessarily ambiguous. As David Cohen put it in Rolling Stone, Trump "puts out the dog whistle knowing that some dog will hear it, even though he doesn't know which dog."

It's far too early to predict that the Supreme Court could take up a Trump-era dispute that would somehow force the justices to revisit the Brandenburg test for the digital age, but the timing would be fortuitous. After all, it took 50 years after Schenck gave us "fire in a crowded theater" for the Court to redefine the limits of American citizens' First Amendment rights in Brandenburg; now, 50 years after Brandenburg, conspiracy theories in the age of the Internet offer yet another chance for the Court to define exactly where "free speech" stops and violence begins.