This article from UCLA (No longer available) has an amusing bit of logic to it.

But he was unrepentant, and blamed the west’s view of Islam as the primary cause of the violence.

“This protest is not about the cartoons, offensive as they are,” he said. “There has been intense psychological pressure on Muslims. We have heard western politicians relate our faith to terrorism, over and over again, and it is too much. This was the response.”

So… Western politicians equate your religion with hurting people and breaking things. So to protest this association, you hurt people and break things? ;)