I think it may have an effect on society. I am kind of torn on how to answer this. Some people have a difficult time on how to separate their times playing video games and their time in reality but I don't think it just happens like that. I have seen things in the news about people who were too obsessed in playing video games that they made a choice that they would probably regret for the rest of their life. Now I feel like some people on here and myself are only talking about the video games part instead of the television and movies part so I will talk about that now as well. I feel like television and movies don't make as big as an impact as video games does on the question you are asking but I haven't seen all television shows and movies so I could be wrong. I am not saying that if you play a video game, you will be messed up for life. Nothing like that. Video games actually help people at times, believe it or not. So I think there are pros and cons on playing video games with violence and watching the television and movies with violence.
Do not define your world in black and white because there is so much hiding amongst the greys.