Civil Unrest?

Anyone ever noticed how, whenever there is any kind of civil unrest, of which there has been plenty in the world lately, there is always the small element that just want to cause mayhem, throw rocks and petrol bombs at the police or other authorities, and generally turn, what may have been an otherwise peaceful demonstration of anger at a particular situation, into a riot?

You also find as a matter of course, that  these rent-a-mob thugs are so brave that they are always masked, lest they be identified by their mothers, girlfriends, partners etc. Not to mention the fear of actual arrest and incarceration.

I attended several such demonstrations as a young student, and never once did anyone feel the need to a) indulge in any kind of violence (apart from some mild name-calling) and b) mask our faces, because we were proud of the fact that we could demonstrate against 'the bomb' or 'the war' or anything else, without resorting to that kind of behavior.

I think the worst we got up to was a passive linked arm sit-down, until we got dragged off by the police. We were given a telling off, and then some wag would realize that it was after opening time, and that was far more important!