Most likely your typical white trustafarians who wear balaclavas, fashion themselves "anarchists" and commit violent vandalism in the name of addressing economic disparities. In simpler terms, rich white kids who cover their faces and smash storefronts. They probably knew nothing more than regurgitated talking points about the current situation in Greece. They're just looking for an excuse to break stuff and get on the news.
When they assemble, they tend to look like this:
