No, because we do it now anyway. We rate our movies and disallow people of certain ages from seeing or buying them. Adam Lanza was intensely into violent gun video games. The Colorado shooter was dressed up like a Bat Man character.Violence in video games and movies, or lack of mental illness treatment, not guns, cause gun deaths. Another duh! These games and movies are just as popular in other countries, and there are mentally ill people all over the world, but other countries don't have the same rate of gun deaths because they don't allow every nutter to own a gun. And who's going to pay for mental illness treatment? Who decides who's mentally ill? Plus a little thing called freedom of speech might make it hard to censor games and movies.
Who will take care of the mentally ill and decide on who is mentally ill? We did it years ago. It was called being committed. If a police officer or family member suspected a person not of sound mind, they took him or her to court and they were committed to a care facility. As time went on, the courts decided that by committing people who committed no crime, it violated their Constitutional rights. Did they rule that in these other countries you speak of?
So we were forced to open the door and let them all go, and they still roam among us today. It was Geraldo who started the movement when he had his own hour television show every week back in the 70's.