The U.S. Supreme Court heard arguments on Monday in a case that could determine whether the First Amendment of the Constitution protects death threats made on the Internet as free speech.

The case involves a man who vented against his estranged wife as well as others on Facebook, posting graphic lyrics threatening to kill them, and how the court rules could have reaching effect on the limits of free speech online.

The case, Elonis v. United States, centers on Anthony Elonis from Pennsylvania after he posted graphically violent rap lyrics on Facebook about his wife. His venting started after his spouse left him, taking the couple's two children. Elonis, who often posted under the alias "Tone Dougie," began writing about killing his wife in the form of rap lyrics, attacking a kindergarten and committing violence against an FBI agent who visited him in the wake of the online threats.

"There's one way to love ya, but a thousand ways to kill ya," he wrote. "And I'm not going to rest until your body is a mess, soaked in blood and dying from all the little cuts. Hurry up and die bitch."

His wife said she felt threatened and sought protection from the courts. Elonis was indicted on five counts of interstate communication of illegal threats. The jury convicted him on the grounds that these represented true threats and sentenced him to four years in federal prison. However, Elonis maintains the posts should not be taken seriously, and he was exercising his First Amendment right to free speech.

Elonis subsequently appealed the case to the Supreme Court.

The petitioner's attorney said his client didn't intend to place his wife in fear and that the posts all came with disclaimers stating not to take it seriously. The government, however, said the posts were threatening and that Elonis knew the effect they would have on his wife.

In Supreme Court, some justices seemed concerned that the government's position is too broad and risks sweeping in language protected by the First Amendment, but there was little agreement over what standard to use.

"How does one prove what's in somebody else's mind?" Justice Ruth Bader Ginsburg said, according to The Associate Press.

Elonis' attorney, John Elwood, said the writer's intent could be understood by context through a search of cell phone records and other evidence. He cited another case where in a video game chat room, teenagers insulted each other with one making a comment about shooting up a kindergarten after another teen called him crazy. The teenager threatening the kindergarten wound up getting thrown in jail after a woman in the same chat room reported the comments.

Chief Justice John Roberts suggested the government's standard simply should be whether a reasonable person familiar with teenagers in video game chat rooms would view it as a threat. But Elwood argued that everyone had a different view of context, and a better standard would be to look at the intention of the speaker or writer.

Justice Elena Kagan asked whether there should be a "buffer zone" under the First Amendment "to ensure that even stuff that is wrongful maybe is permitted because we don't want to chill innocent behavior."

The Supreme Court has said that true threats to another person are not protected speech under the First Amendment, but "political hyperbole" or "unpleasantly sharp attacks" [comedy for instance] are protected speech.

The case has drawn widespread attention from free speech advocates who say that comments on Facebook, Twitter and other social media can be hasty, impulsive and easily misinterpreted.

"A statue 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," said a brief from the American Civil Liberties Union.

The ruling in the case won't be made until the Summer 2015.