Ok, so there's plenty of parents that are super anti-video game advocates. Personally I allow my 7 year old daughter to play an assortment of video games. And it's a wonderful outlet for her. And it also makes her happy and she enjoys the community and social aspect of playing games with other children. And yes. Sometimes there is violence. With the games she plays though at her age it isn't exactly gratuitous. But there's gratuitous violence all over the world. And the majority of these children that behave aggressively, violently, or commit criminal acts... either suffered from untreated mental illness or had documented poor parenting. If we teach our children well enough and teach them right from wrong and be good, involved, mindful parents, then these children will understand their ability to differentiate between real life and what's just a video game. Unacceptable behavior is all around them. To point the finger solely at video games is silly and ignorant. And personally, I think It's a scapegoat for parents with misbehave children. That's just my opinion and may not always be the case. But I truly believe It's the morals we instill in them that keep them good, and growing into productive, prospering members of society.
Here are a few of the articles i read while forming my own educated opinion on the matter, certainly worth the reads. And each one definitely show both sides of the matter. But I feel it's pretty clear which argument consistently prevails.
http://www.debate.org/opinions/do-violent-video-games-cause-behavior-problems