I think most people believe that the "yelling fire in a crowded theater" precedent came from an actual case about someone yelling "fire!" in a crowded theater.

I think most people believe that the "yelling fire in a crowded theater" precedent came from an actual case about someone yelling "fire!" in a crowded theater. As opposed to being a hypothetical situation invented to justify the use of state violence to silence anti-war protestors. No one goes around saying "you can't be against a war!" when that is the actual precedent that was set in that case.