The furore over Kate Middleton’s body and the film of the Prophet share an important feature – outrage protects the body of the believed and the offending article (the photo/the film) both offend the believer.
In the west few believe in Royalty and it is the young woman to-be-Queen who believes in herself and as such appeals to the law as defence. In Islam people do believe in the Prophet and appeal beyond law to themselves. Kate Middleton has a private belief system where personal models of society that are sacred are upheld by the law. For the faithful the public belief system is sacred itself.