During the May Day protests a subset of protestors called the Black Bloc (they wear Annoymous masks and black shirts/hoodies) deliberately targeted photographers with the intent of destroying gear.
Buzzfeed collected Tweets from photographers accosted and reports including things such as: "@Steffikeith Some black bloc man bigger than me with bandana tried to take my camera from me violently" and C.S. Muncy (a photographer covering the event) told Buzzfeed "One girl walks up to one of the photogs (from Reuters) and nailed him right in the face. He popped her right back."
At first people believed it was a spontaneous outbreak of violence against reporters...or anyone with a camera. However, a post from the Anarchist News makes it appear that anyone with a camera is a planned target of violence. "To our enemies: if we won't hesitate to directly confront hundreds of cops and to destroy property, what makes you think we hold the lens of your camera to be sacred? You want to preserve your four thousand dollar camera to watch us break everything else? We are not doing this for you, and this is not a game. You clearly do not understand that there is no exception. We feel nothing but contempt for you cowardly spectators. You'd better watch your necks next time."
If you are going to be documenting the protests - please be careful out there. It's turned from protests to attack gangs of thugs in far to many cases.