Companies routinely censor the American version of Japanese video games, yet Japan has a much lower violent crime rate than the US.  In fact, The National Institute on Media and the Family says playing these games can have positive effects.  They can introduce children to technology and help them practice following directions, problem solving, logical thinking and fine motor skills.

The game industry reached $15 billion dollars in 1998 and, according to the Annenberg Public Policy Center, 62% of American families already had video game equipment before that year even began.  As for ratings, it's been shown that "Parental Discretion" advisories may actually make entertainment more attractive to kids.  Banning them would have a similar effect, while chipping away at the First Amendment right to free expression.