Based upon a character in Stephen King's "The Stand", a monster shouter is one who, for no reason other than their own belief that everything and everyone around them is part of a conspiracy which will surely bring about the world's end, takes to the streets, the internet and anywhere s/he can gain public voice to rail aloud that the end is coming and we are all surely doomed.
When the H1N1 flu virus hit the US en masse, monster shouters took to the streets proclaiming this was "judgement" and "the end of days".
by Dante's Infernal July 16, 2010