^^^^^^^ CB: The legal standard for whether speech is not protected by the First Amendment is so-called "incitement to imminent lawless action"
http://en.wikipedia.org/wiki/Brandenburg_v._Ohio
Brandenburg v. Ohio, 395 U.S. 444 (1969), was a United States Supreme Court case based on the First Amendment to the U.S. Constitution. It held that government cannot punish inflammatory speech unless it is directed to inciting and likely to incite imminent lawless action. In particular, it overruled Ohio's criminal syndicalism statute, because that statute broadly prohibited the mere advocacy of violence.