Washington (CNN) The Supreme Court ruled Monday in favor of a Pennsylvania man who posted several violent messages on Facebook and was convicted under a federal threat statute -- the first time the Court 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.

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The Court held that the legal standard used to convict him was too low, but left open what the standard should be. It is a narrow ruling and the Court did not address the larger constitutional issue.

The case concerns a Pennsylvania man, Anthony D. Elonis, who posted several violent messages on his social media account after his wife left him. He claimed he was an artist who turned to rap lyrics for therapeutic purposes to help him cope with depression.

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