Islam has taken everything from its wretched believers. They are robbed from their identity and self pride. All they have now is Islam. That is why Islam for Muslims is more than just a religion. It is their identity. When you criticize Islam, they perceive it as an attack on their identity and cringe with pain. They take that not only as an insult but also as an assault on their person. Like a corned animal they become vicious and fight back with all their might - a fight of survival. That is why you see such a violent reaction to a few silly cartoons.