I think it's the media in general. If you're going to blame someone for violence, blame the news. They report 80% tragedy and thus, humans don't know any better. Video games do (and apparently have been proven) to cause violent thoughts, but violent actions produce violent thoughts, what can I say? 1000's don't go out after playing GTA or Scarface and Curb stomp someone, steal a car... or commit any felonies for that matter. A lot use video games as release.
In short, I don't hate the haters, I pity their ignorance.