Some believe that it's never OK to gratuitously attempt to hurt the feelings of large groups of people. They are wrong. It is not only right, but in some ways incumbant on us to do so, particularly when their feelings get hurt due to a worldview that, were it not shielded from criticism by being labelled religious, would have them in a room with padded walls, and they think they have a right to enforce their views via threats and force.
It is high time such people learn, be they Muslim, Catholic, or any other belief system, that no one else is under any obligation to avoid engaging in behavior that they arbitrarily declare offensive, and the louder they scream that we shouldn't, and threaten us with violence, the more of it they should see. We'll destroy crackers if we want to, draw pictures of Mohammed if we want to, and yes, tear up pages of The God Delusion if we so desire. That's what free speach MEANS - my speech doesn't have to conform to your views.