Washington (KRON/CNN) — The Supreme Court on Monday ruled in favor of a Pennsylvania man convicted under a federal statute of making violent threats on Facebook, in a decision that raised the implications of free speech on social media.

The Court said that it wasn’t enough to convict the man based solely on the idea that a reasonable person would regard his communications as a threat.

“Our holding makes clear that negligence is not sufficient to support a conviction,” wrote Chief Justice John Roberts.

The Court held that the legal standard used to convict Anthony D. Elonis was too low, and the justices sent the case back to the lower court without clarifying exactly what the standard of proof should be.

The narrow ruling did not address the larger constitutional issue over free-speech.

The case stems from a conviction over violent messages Elonis posted on his social media account after his wife left him. He claimed that he was an artist who turned to rap lyrics for therapeutic purposes to help him cope with depression.

“There’s one way to love you but a thousand ways to kill you,” he wrote in one post.

“Enough elementary schools in a ten mile radius to initiate the most heinous school shooting ever imagined,” he wrote in another.

Elonis was convicted for violating a federal threat statute that makes it a crime to threaten another person.

Menlo Park-based Facebook was not a party in the case.

Elonis appealed his conviction to the Supreme Court arguing that the government should have been required to prove that he actually intended to make a threat before sending him to jail in a 44 month sentence. Instead, the jury was told the standard was whether a “reasonable person” would have understood the words to be a threat.

John P. Elwood, Elonis’ lawyer stressed in court briefs that his client often posted disclaimers noting he was only exercising his freedom of speech. “The First Amendment’s basic command is that the government may not prohibit the expression of an idea simply because society finds it offensive or disagreeable,” Elwood wrote. At his trial, Elonis testified that his Facebook posts were partly inspired by rap star Eminem.

Elwood said that he is confident that his client will be vindicated when lower courts weigh in, possibly at a new trial.

In court briefs Solicitor General Donald B. Verrilli, Jr defended the conviction. “He was aware of the meaning and context of his Facebook posts, and those posts communicated a serious expression of an intent to do harm,” Verrilli wrote. He also said that there was no comparison between Elonis’ threats and the protected speech of commercial rap artists that are made in a “very different” context.

But the ACLU filed a brief in support of Elonis arguing that context matters. “Words are slippery things,” wrote Stephen Shapiro. The civil liberties group’s legal director said that a statute that limits 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.”

According to the Justice Department, 63 people were indicted on federal charges of making illegal threats in the 2013 fiscal year. That’s up from 53 cases the previous year.