Bethany Austin did nothing society would reasonably call wrong. She received, without asking, sexually explicit images that her fiancé’s paramour sent to a shared cloud account. She quietly called off the engagement.

That’s where the story should have ended. But her former fiancé decided to spread a hurtful and untrue rumor that he had ended the relationship because Ms. Austin was crazy and refused to cook and clean for him. To clear her good name, Ms. Austin wrote a letter to her friends and family explaining what really happened. She attached some of the images as proof. Now the ex‐​fiancé and his paramour are using Illinois’s “revenge porn” law to punish her for speaking, and the state is happily obliging.

Illinois law makes it a felony to disseminate sexual images that a reasonable person would know are meant to remain private and would or should know that the subject did not consent to the dissemination. This law is the most expansive in a nationwide legislative effort to combat the grotesque practice of “revenge pornography,” where a jilted lover maliciously spreads private images far and wide after a break‐​up. Unlike other states, Illinois law is not limited by the intent of the person disseminating the images.

Under the First Amendment, a law that discriminates based on the content of speech is unconstitutional. Private parties can still sue for defamation. These suits are hard to win when the offending speech is about matters of public concern—like politics, celebrities, and news stories—rather than private matters, like malicious slanders about your neighbors’ children. This public/​private distinction doesn’t matter in criminal law.

The government can also regulate the time, place, and manner, of speech as long as the law applies equally to all speech. In Reed v. Town of Gilbert (2015), the Supreme Court held that regulations on when and where signs could be displayed may have been constitutional, but a sign code with different rules for religious and political signs was unconstitutional.

Additionally, laws can regulate unprotected speech—including threats, obscenity, and incitement to violence—but if the law deters a significant amount of protected speech in addition to the unprotected speech it targets, then it is unconstitutionally “overbroad.”

Responding to the complaints of the ex‐​fiancé and his paramour, Illinois charged Ms. Austin under the revenge porn law. She moved to dismiss the criminal charges against her, citing the First Amendment protections for her speech. The trial court found the law unconstitutional, but the Illinois Supreme Court reversed.

Cato, joined by DKT Liberty Project, has filed an amicus brief supporting Ms. Austin’s petition to the U.S. Supreme Court, arguing that the Illinois court incorrectly distinguished between private and public speech and that, in any event, the state law is not a content‐​neutral time, place, and manner restriction, and is overbroad.

The Supreme Court will decide whether to take up Austin v. Illinois later this spring.