Un-tongue in cheek, they may indeed be Hoffernian 'true believers' - if they're not simply #$$@*&!!s having their idea of 'fun'.

While that may explain (to a degree)it doesn't excuse or condone. Most of history's atrocities were (and still are) committed by "true believers" of whatever political/religious/social/etc. dogma you wish, from Pope Innocent thru Stalin to Timothy McVeigh.

Not a comforting thought.

Best, Greg