The political philosophy of many, but not all, of the people who participate in the black bloc is the political philosophy of anarchism. That is why people associate anarchism with disorder or violence. That is really far from the truth of what an everyday anarchist actually practices and believes.
Anarchism is based on mutual consent, and the so-called violent aspect of black blocs and anarchism really needs to be understood. I mean, can you really commit an act of so-called violence against a window, or is an act of violence something that you commit against a person? What most people in the black bloc would say is that it is not violence to break a window.