I think its a bunch of crap that people blame the games their kids play for negatively influencing them. Parents just don't want to own up to their own failings and lack of attention to what is going on in their children's life. There is a ratings system for a reason. It is up to the parents to make sure that their children are playing appropriate games for their age. The kids may learn some of what they are doing from a game they are playing and shouldn't be, but in the end they probably learned most of what they are doing from their own parents.
I play a lot of games on XBL and am constantly having to put up with a bunch of 10 to 13 year olds being obnoxious towards me because I just violated their whole team. If I had been that way to anyone when I was a kid I would have gotten the crap kicked out of me by my parents and I'd never see my console again except maybe the few bits and pieces that were left after they destroyed it to teach me a lesson. I'm not saying that is the correct way for a parent to handle their children but neither is completely avoiding this issue entirely and having absolutely no control over what is going on. Somewhere in the middle is where things need to be.
Games themselves are not to blame for what is wrong in this world. It is up to each individual person to learn from their experiences and act in a way that is both respectful of the other people around them and responsible. Just because I enjoy stealing someones car and running over pedestrians to start a police chase in a GTA game or that I seriously enjoy sneaking up behind someone in a FPS and slowly taking aim at the back of their head before I pull the trigger so they can see it all in the kill cam doesn't mean that I am going to go out and do either in real life.