It's a lot like blaming music for violence ... if it wasn't the music/video game/whatever, something else would have led them to be violent. The person has to be a bit off in the first place if something like that makes them go out and commit acts of violence.
And I love Tetris and get so frustrated ... I do get serious cases of (temporary) profanity playing the Xbox. I think I need a Parental Advisory sign on my front door ... But if violence in movies, video games, songs, etc. caused violence, my husband would be a dead man by now.