"Shouting fire in a crowded theater" is a popular metaphor for speech or actions made for the principal purpose of creating unnecessary panic. The phrase is a paraphrasing of Oliver Wendell Holmes, Jr.'s opinion in the United States Supreme Court case Schenck v. United States in 1919, which held that the defendant's speech in opposition to the draft during World War I was not protected free speech under the First Amendment of the United States Constitution.
