The metaphor of "shouting fire in a crowded theatre" was actually used in a Supreme Court ruling in Schenck v. United States, which justified putting a guy in p

The metaphor of "shouting fire in a crowded theatre" was actually used in a Supreme Court ruling in Schenck v. United States, which justified putting a guy in prison for speaking (distributing leaflets) against the military draft. This decision was later overturned by Brandenburg v. Ohio in 1969. (Source: wikipedia)