Many imams issue fatwas against those insulting Mohammed. But, realistically, how can you insult Mohammed? Call him a thief, a bandit, a murderer, a kidnapper, a rapist, a terrorist or even a pedophile and you can cite the text from their holy books to confirm it. Yet they will take offense if you do.
“Yet they will take offense if you do.”
Been my experience that the perpetually offended need no reason to be offended.
If they are not offended they are like the dead parrot up thread, best to beat them to find if they are living. If they are beat them some more, if they dead mock them.