Now we're getting to the point of pointing fingers at media as the "cause" for people hurting each other.
I think blaming violent video games, tv shows, movies, etc. is an excuse of cause, not an explanation. I grew up with exposure to all of them (sci-fi and horror are my father's favorite genres). I still watch/play all. I am not violent, I abhor violence in real life, and I'm not afraid of ghosts or being attacked by maniacs with chainsaws. Of course, my father also raised me to be capable of rational thought, to think of of consequences and to be considerate of others.
If people's minds can be swayed so much by such influences then we also need to get rid of books, stop telling stories, and ban music. Exposure to media may be placed as a point on an individual's timeline, but if as a species we have become that easy to influence then the world better end on the 21st because we're too broken to fix.
We have to stop treating things that may magnify the issue (or chance of it) as if they were the issue. It's like believing getting wet or getting chilled causes a cold. It doesn't. It just makes it more likely you'll get sick. Also, for as much as those things may increase the chances of a problem, you have to acknowledge there are things that can strengthen resistance to them. To do otherwise is intellectually dishonest.
Oh, and everyone/nobody having a gun doesn't fix the issue of people harming each other either. That would be like wiping your nose in order to cure your cold.