The phrase originally came from Schenck v. US[1], in which Justice Oliver Wendell Holmes, Jr. said: The most stringent protection of free speech would not prot

The phrase originally came from Schenck v. US[1], in which Justice Oliver Wendell Holmes, Jr. said: The most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic. Few recall that Holmes used this argument to justify imprisoning a group of socialists for the crime of attempting to mail leaflets. These leaflets protested US involvement in The Great War and urged people to protest the draft. 1. https://en.wikipedia.org/wiki/Schenck_v._United_States https://en.wikipedia.org/wiki/Schenck_v._United_States