I dunno, both sides of the political spectrum have a long history of trying to censor one form of popular media or another.
The movie industry for the most part avoided this nonsense because it took a step to regulate itself before the politicos and everyone else could get a chance to impose some kinda crap on themselves.
The video game industry sort of did its thing with the ratings system but it's never really had the level of effectiveness as movie ratings.
The only thing the government can do is provide parents with the tools for making decisions about what their kids can see, play, listen to, whatever. For the most part those tools are out there. Movies and video games have ratings. Music has parental advisory labels. TV has a ratings system and the v-chip for locking out programs that parents don't want their kids to see.
I know I see commercials all the time from the cable company and whoever else showing exactly how to program parental locks. The tools are there. So if parents give a shit about what their kids see on tv then they can do whatever they feel like with the locks.
But really, why not just leave it up to parents to be irresponsible with their kids if they want to? The ratings are there and if they want to pay attention to them they can. My own parents used the ratings. Hell I distincly remember the ordeal I had to go through to get them to let me buy Mortal Kombat.
But there's plenty of other parents who like to buy their ten channels of HBO, Cinemax and whatever else and just let their kids watch whatever the hell they want. Okay so maybe those kids heard some cuss words, saw some people get killed, or got to find out how great a thing boobs are a little earlier than maybe they should have, but in the end are those kids really messed up in the long run?