This doesn't only apply to men. Just sayin'. But maybe women have different motivations.
For example, I often watch psycho thrillers or read them as well, but I would never hurt anyone. Usually the psychological aspects fascinate me, and I try puzzling out how the minds of such people work and how they develop a certain way and what's going on 'up there.'
In addition, I love boxing and shit. Sometimes I imagine kicking someone's ass, though, if they hurt me or someone I love. Never actually do it because fantasizing about it suffices, and going to jail isn't worth kicking someone's ass. Besides you can't educate people, so they'd stay stupid and ignorant anyway. So in the end, I'm the only one who would lose. But no one gets hurt by me jabbing, kicking, and cross punching the effer to bits in my vivid imagination.