Violence has been depicted in books and plays for hundreds of years. Grimm's fairy tales have it. Shakespeare has it. Walt Disney movies, made for children, such as "Bambi" and "Pinocchio" have it. When Disney movies are shown there are often a few of the younger children who cry at certain scenes, and some parents will not take their kids to the classic Disney movies. Of course classic adult movies have it too. But something has changed lately.
The violence depicted in today's movies is extreme and graphic. It is very different from the shoot-outs in the old Westerns, where the guys in black hats expired bloodlessly while delivering a few choice remarks.
Psychologists tell us that when you watch a movie or play you vicariously participate in the action. When the hero kills the villain, you experience strong emotion.
Video games are fundamentally different. The player experiences the events, not as a spectator, but as the direct result of his physical actions. He selects the victims. He aims the weapon. He pulls the trigger. Gruesome carnage results. This is a step too far. How long will it take until the game becomes stale, and an urge to do it for real develops? Sadly there are some in our society who cannot resist the urge.
President Obama thinks he can violate the Second Amendment and impose an ineffectual ban on certain models of guns. If you would allow that, why not violate the First Amendment and ban the sort of video games I have described.