What does logic have to do with it?
People like to destroy stuff. I think it's just the destruction they like, and I don't think it goes farther than that. I suspect there are a lot of terrorist mentalities out there, but they haven't got a cause. Do they really need one? No, I don't think they do.
I think it's mob mentality, lose yourself in the group, hide in the dark, then strike and run.
It happens if a group's sports team doesn't win. It happens if they DO win. It's why soldiers shot the nose off the Great Sphinx. It's why vacant buildings are vandalized. It's why a couple of boys walking down the street have to throw a rock through a window.
Is someone going to pick them out of the mob and arrest them? Probably not, but if they do, there won't be any great penalty for it.
Sue