Very true, but it still oes come down to the parents. If the parents of the mass majority aren't doing their jobs properly, then there's nothing we can do. The fact that such violence is on TV or in games doesn't mean a kid should be subjected to it.
That said, I've been around violent TV and Games my entire life and haven't once decided to go out on a killing rampage. I thank my parents upbringing for that and certainly not my friends growing up since most of the ones I had at an age where we were most impressionable grew up to mostly be troublemakers. They all pretty much had the same access to the media's I did and since we were all friends, we all influenced each other, and yet we ended up differently.
Leads me to believe our parent have the most influence of us as children, we see them as authority figures, we look to them ultimately for guidance and, like monkeys, we follow by their example.