Social media sites face many choices when they set rules for users. How much speech is permissible? Will conversations be “anything goes” or strictly moderated for relevance and decorum? Will moderation decisions be automated, human, or a mix? Different sites have made different choices, and that’s as it should be. Indeed, the First Amendment requires that sites have the freedom to make these decisions for themselves.

Although social media may be a relatively new medium, long‐​established First Amendment principles give sites the right to control what content they host, just as newspapers and book publishers have a right to select the editorials and manuscripts they print.

Some states, including Texas and Florida, have attempted to infringe the First Amendment rights of social media companies in blatant ways, such as by forcing sites to host user content they do not wish to. And now New York State has joined the fray with its own unconstitutional intrusion into the editorial freedom of social media sites.

New York recently enacted an “Online Hate Speech Law” that requires social media sites to promulgate policies governing so‐​called “hateful conduct” and create “mechanisms” by which users can report such conduct. “Hateful conduct” is defined by the statute to include online speech that can “vilify” or “humiliate” a group or a class on the basis of race, sex, and other traits.

New York’s law was soon challenged in a lawsuit brought by several operators of online platforms, including law professor and First Amendment expert Eugene Volokh. As the operator of the “Volokh Conspiracy” blog, which allows user comments, Volokh himself would be forced to comply with the law’s requirements.

A district court ruled in favor of Volokh and blocked the law from going into effect, holding that it likely compelled speech in violation of the First Amendment. The court found that the law impermissibly required sites to publish a “hateful conduct” policy even if they would prefer not to publish any such policy, forcing them to speak when they would prefer to remain silent.

New York appealed that decision to the Second Circuit, and Cato has filed an amicus brief urging the Second Circuit to affirm the lower court and hold the law unconstitutional (with thanks to attorneys Joshua Zuckerman and Brian McCarty of Gibson Dunn, who drafted the brief on behalf of Cato).

In our brief, we explain why the law’s “reporting mechanism” requirement violates the First Amendment rights of both social media sites and their users by chilling free expression. Some sites may prefer not to have a reporting mechanism for so‐​called “hateful conduct,” given that most of the speech falling under New York’s mandated definition of that term is itself lawful speech protected by the First Amendment.

These sites may reasonably expect that if they did have such a reporting requirement, users would naturally self‐​censor for fear of being reported. By compelling unwilling sites to create a mechanism for users to report on each other, the law is likely to stifle the uninhibited flow of speech that these sites would prefer to allow.

Of course, social media sites are free to voluntarily create reporting procedures, and many had already done so prior to New York enacting its law. But the choice of whether to create such a mechanism, how it operates, and what speech to make reportable must be up to each individual site.

New York’s one‐​size‐​fits‐​all definition of “hateful conduct” puts a thumb on the scale, with the clear aim of inducing self‐​censorship of some lawful speech that New York would prefer to suppress. The Second Circuit should make clear that states can’t use mandates like “reporting requirements” to indirectly achieve online censorship that states couldn’t impose directly.