In November 2014, a Pennsylvania man was found guilty in federal court after posting messages on Facebook about killing his estranged wife. He said he wasn’t serious and that his posts were akin to rap music lyrics.

The jury didn’t see it that way. Anthony Elonis of Bethlehem, Pa., received a prison sentence of three years and eight months. As of January 2015, the case was under appeal.

Elonis’ words were ugly. In one post about his wife he wrote, “There’s one way to love you but a thousand ways to kill you. I’m not going to rest until your body is a mess, soaked in blood and dying from all the little cuts.”

In another post he wrote, “I would have smothered [you] with a pillow, dumped your body in the back seat, dropped you off in Toad Creek and made it look like rape and murder.”

Elonis argued that his posts were a spontaneous form of expression that shouldn’t be considered threatening because he didn’t really mean it and that they should receive protection under the First Amendment.

The prosecution contended that it doesn’t matter what Elonis intended, that the test of a threat is whether his words would make a reasonable person feel threatened. His wife testified that she did. The jury and one appeals court thus far have agreed with his wife.

A brief from the American Civil Liberties Union and other groups supporting Elonis, along with free speech, contended, “A statute that proscribes speech without regard to the speaker’s intended meaning runs the risk of punishing protected First Amendment expression simply because it is crudely or zealously expressed.”

A brief from the National Center for Victims of Crime supporting the prosecution, along with crime victims, contended that judging threats based on the speaker’s intent would make stalking crimes more difficult to prosecute. “Victims of stalking are financially, emotionally and socially burdened by the crime regardless of the subjective intent of the speaker,” according to the organization.

Elonis also contended that his posts were an artistic way to vent his frustration after his wife left him and that they were influenced by the rap musician Eminem, who has fantasized in song lyrics about killing his ex-wife.

In the past the U.S. Supreme Court has ruled that “true threats” to harm another person are not protected speech under the First Amendment, as opposed to “unpleasantly sharp attacks” or “political hyperbole.” The key test the courts in general have used, which the prosecution in this case used as well, is whether the threat would make a reasonable person feel genuinely threatened.

Elonis adopted the pseudonym “Tone Dougie” in his posts, rather than use his real name. But that didn’t protect him either. When the authorities got involved, his true identity was quickly uncovered.

Most of us have seen people lose control on Facebook and Twitter, on blogs and in discussion groups, in emails and in texts, letting loose with angry rants, name calling, cursing, threats, or attacks on another person’s motivations, competence, lifestyle, or national, racial, or religious background.

The name for this type of activity is “flaming,” and such words are called “flames.” The Internet makes flaming more common than in other forms of discourse. You’re separated from others by space and often by time as well. By using a pseudonym or handle, you may think you’re invisible. In other settings, if you were to express the same in-your-face abuse, you might get shunned, fired, or punched in the nose.

On the other hand, there’s nothing wrong with debate. You’ll look much better, however, if you attack your adversary’s arguments or actions using rhetoric and perspective rather than gutter talk. Such flaming can reach the level of ritual battle, even art form.

But abusive discourse is the more common type. It isn’t unique to the Internet or to our times.

Founding father Thomas Paine denounced George Washington in an open letter as “treacherous in private friendship … and a hypocrite in public life.”

Essayist Ralph Waldo Emerson said of novelist Jane Austen, “Miss Austen’s novels seem to me vulgar in tone, sterile in artistic invention, imprisoned in the wretched conventions of English society, without genius, wit or knowledge of the world.” In response, philosopher and essayist Thomas Carlyle called Ralph Waldo Emerson “a hoary-headed toothless baboon.”

Today, on the Internet, it sometimes seems that flaming is risk-free. The Elonis court case is the latest example to show that there can be consequences. Be careful out there.