The Supreme Court on Tuesday sided with a man convicted of stalking after he sent hundreds of Facebook messages to a musician in Colorado she viewed as "creepy," drawing criticism from some advocates who said the decision would make it harder to convict people for similar behavior.

The appeal from Billy Counterman asked the Supreme Court to decide what constitutes a "true threat" that can be prosecuted as a crime versus what types of menacing language is protected. In a 7-2 decision, the Supreme Court ruled that the standard prosecutors in Colorado used to convict Counterman violated the First Amendment.

Counterman claimed he did not intend to threaten the musician, Coles Whalen, with his messages. The Supreme Court's decision tosses his conviction but leaves open the possibility that prosecutors could try again under the more rigorous standard. The court said prosecutors must show a defendant acted recklessly, meaning the person "disregarded a substantial risk that his communications would be viewed as threatening."