Protesting when everyone has a camera
Anonymous (Internet freedom, anonymity, Scientology, cats, anything really)
The Black Bloc (Left wing anarchist, antiglobalization, Wall Street and Great Recession related stuff)
The Immortals (Neo-Nazi/Fascist?, anti-immigrant, racist)
Pussy Riot supporters (Feminist, anti-Putin, Russian Orthodox Church related stuff)
Anon was really on to something when they started wearing those masks. I'm sure there are other examples. Is this a thing now? It seems like you can't pull off a demonstration without masks. After the Vancouver hockey riots the local police monitored Facebook and Twitter and tracked people down from pictures that were posted. In some countries any kind of rabble rousing whatsoever could land you in trouble. Even if what you're doing isn't illegal you risk being outed online and having your employer find out about your politics.