I think that it depends on the person... if somebody is a violent person and plays GoW2 or GTA4 then of course they are going to go shoot up their school or somethin' (LOLZ!). But somebody like me or most of the people here wouldn't think of doing something like that, the games may give you ideas... but not cause you to actually rob a bank or hold out at a McDonalds with some tommy guns. So if a violent person plays a violent game... of course that will give them some ideas and perhaps make them worse. But a non-violent person will just have fun in the game knowing that none of this nonsense will actually happen. Unless the Locust do come... I wanna be Cole Train!!!!
IMO video games are just a scapegoat, something to take the blame for the failures of the parent, or the guardian. Its not hard to read the labels, and control what your child plays, but things area changing we cant deny that. I imagine when we start having kids we will be able to realize how pathetic we actually are, but we will be at an advantage over our parents as we were more exposed to the systems, and games. In the end we will have as muck control as "modern" parents, but more knowledge.
I picture it more-so as a way to channel emotions; like a stress reliever of sorts. I think that the worst that can happen is a small child gets paranoid, but that's more of horror's fault, and you'd have to be a really dumb parent to let a child play like... Silent Hill or fear or some ****.
Kind of how I feel, but kind of not. I say it does depend on the person, but if a violent person plays violent video games then they will think more and have more violent ideas to think about, but not necessarily do. Then if someone not very violent plays violent video games then they will do the same, but will never think of actually doing it. Take me for example, I'm not violent at all, I might raise my voice if I'm angry, or I'll fight back if needed, but I won't do anything unnecessary. I play a descent amount of Halo 3 and I will once in a while think about what it'd be like being shot with a BR or something, but I would NEVER do it to someone unless proven necessary. Some people take it differently than others, and I think it's worse to expose violence at a smaller age. Smaller kids don't think much about things, and will just absorb the violence just like he/she does with any other thing. So video games do hurt you in a sense, but they almost definitely won't change your life as long as you are exposed to them at the right time in your life.