My answer to these types of stereotypes is this:

"Wow, Hitler, Stalin, Pol Pot, Mao Zedong...instert name of evil nasty dude here...must have watched lots of horror movies, listened to lots of evil metal music and played lots of violent games.

Oh wait, given their time in history, probably not. Damn, your theory seems to fall done there...and for the five thousand blood soaked violent years of mankind prior to movies, metal music and video games."