Is there not something a little bit fascinating in realizing that regardless of the particular political belief driving them to do something, there must be something that goes haywire in the mind to think that "this is so right that I am justified in destroying property, people to get it done". Maybe when you get to that state (regardless of the particular issue at hand), you should ask as a final check "am I absolutely sure I'm not crazy"? (lol)
Also makes you wonder if, for all the convictions you have about some issue, maybe you would equally be as passionate on the other side of it if you had simply been raised by different parents, been fed different points of view, etc. Maybe our belief that we are morally right is not as great a motivator of action as we think it should be?