Dunno about psn, but on Xbox you can pretty much block everything based on the ratings. The children aren't even able to play the game and the content is filtered from the feed. I believe there's also a way to restrict online chatting to stop people from trying to hook up with your kids IRL.Have people figured out what limitations psn and xbl have? I need to check later as I don't want my daughter seeing any old shit - hopefully if you can't filter you can at least disable the live from PlayStation feed completely (or whatever the Xbox equivalent is). My son is older so not so much of an issue
You can also limit the playtime of you think your kids are spending too much time gaming.