If bomb threats or yelling fire in a crowded theater aren’t protected speech under the First Amendment, should posting violent threats on Facebook to kill someone or shoot up a kindergarten class be protected?

That is basically the question posed by oral arguments in a recent case heard by the U.S. Supreme Court in Elonis v. United States.

Anthony D. Elonis of Pennsylvania was sentenced to 44 months in prison after several particularly violent Facebook posts that began in 2010 when Elonis’ wife moved out with their two children. Elonis, writing in what is described as rap-style music lyrics, wrote there were, “a thousand ways to kill ya, and I’m not gonna rest until your body is a mess, soaked in blood and dying from all the little cuts.” After Elonis’ wife was granted a restraining order from a judge, Elonis asked in a post if the order was “thick enough to stop a bullet.” In regard to an FBI agent who questioned him, Elonis posted about killing the agent and of carrying out a school shooting at a kindergarten.

A jury convicted Elonis for posting threatening messages and a judge upheld the verdict on the grounds a reasonable person would see the messages and think they were threats. Elonis is arguing his statements are free expression, comparing them to rap lyrics that are often graphic and violent. Elonis’ attorney argued before the Supreme Court prosecutors should have been required to prove that Elonis actually intended to scare and intimidate people, not just that the posts were perceived as threatening.

Requiring prosecutors to prove Elonis actually intended to kill his wife is asking the impossible. As Justice Ruth Bader Ginsburg asked during oral arguments, “How does one prove what’s in somebody else’s mind?”

The Elonis case should be relatively easy to decide if it existed in a vacuum. A reasonable person involved in the situation felt threatened enough by Elonis’ comments to ask for a restraining order and the threats prompted at least a cursory investigation by the FBI. Those comments should not be protected by the First Amendment and Elonis’ conviction should be upheld. Justices must be careful to limit their intrusion on the First Amendment and follow the precedent of cases like Flynt v. United States that have upheld protection for speech that is crude and offensive.

Sometimes common sense is indeed the best legal justification in complicated matters. As Justice Oliver Wendell Holmes reasoned in the 1919 case Schenck v. United States, the most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic. That logic should extend to harassing threats like those made by Elonis.