This law blog reports that the European Union is criminalizing "condoning, denying or grossly trivialising crimes of genocide". Even academic historians can get into trouble. The policy seems self-defeating to me -- I tend to discount any story when the contrary point of view is forbidden. I also think that free speech should allow you to trivialize whatever you want to trivialize.
What makes Imus a racist and a sexist is that he is a white man.It is racist and sexist to punish a white man for things that others could say with approval.