Who says a comic from 1918 can’t be funny?
This was very topical at the time.
https://en.m.wikipedia.org/wiki/Shouting_fire_in_a_crowded_theater
The utterance of “fire!” in and of itself is not generally illegal within the United States: “sometimes you could yell ‘fire’ in a crowded theater without facing punishment. The theater may actually be on fire. Or you may reasonably believe that the theater is on fire”.[3] Furthermore, within the doctrine of first amendment protected free speech within the United States, yelling “fire!” as speech is not itself the legally problematic event, but rather, “there are scenarios in which intentionally lying about a fire in a crowded theater and causing a stampede might lead to a disorderly conduct citation or similar charge.”
I think there was probably quite a lot of these pranksters, and a lot of them probably weren’t punished in any way. So at least they get bonked in the head by Everett.