What I find annoying about the Norton situation, is this. For weeks, Norton was making the most vile comments about certain HM's, like Jade resembling a pig, making gay jibes with regard to Tim and Alex, saying stuff like Alex/Sandy/Tim were like lovers, plus other horrible things about the HM's. This was done night after night, in the name of comedy, and to boost his ratings.
But, if any of the HM's, while in the house, had happened to utter his name, and start chatting about him. For example, making jokes about his sexuality, or slagging his show off etc, BB would have cut the sound for legal reasons in case of libel/slander.
So, it seems to me, that as long as you've got a television show of your own, and are promoting a C4 production, you can say what you like regardless of how hurtful or untrue those comments are.