Ken White (of "Popehat" twitter fame) has a great article explaining how this and similar court cases during the first world war are the origin of the (poor) "fire in a crowded theater" argument against certain kinds of free speech:
I never realized that the crowded theater of the idiom refers to WWI and shouting fire means opposing the draft. The metaphorical argument is much less compelling when the crowded theater is actually on fire!
https://www.popehat.com/2012/09/19/three-generations-of-a-ha...