A Colorado free speech case that went before the U.S. Supreme Court on Wednesday could shift the boundaries of what is considered protected by the First Amendment and what qualifies as an illegal threat across the country. Billy Counterman, a man convicted of stalking a Colorado musician, is challenging his conviction on the grounds his unsolicited and unwelcome social media messages were protected free speech. At stake is the legal definition of a “true threat” — a threat of violence that is not protected by the First Amendment.