It's up to the parents to monitor what their children watch. Why are 12-year-olds watching shows with heavy sexual content in the first place?
Because parents have to work, and kids are left alone way too much. Now that 'friends' has gone into syndication, we can see it all day long too.
Dennis Prager had an excellent article about how children are being exploited by liberals
http://www.townhall.com/columnists/dennisprager/dp20040803.shtml