shadzane's got it right. They're angry about Mohammad being drawn (bomb for a turban = bad idea/bad taste!). God/Allah is not supposed to be drawn in human form, as it smacks of idolatry and it got extended to Mohammad as well. That's taking "You shall not worship false images of me" (paraphrasing that) a little far, but different strokes for different folks and all that, as they say.

I did like the virgins comic, though. That was funny!