Today's action -- dubbed #OpBART -- was widely announced through social media sites and the Anonymous network. Anonymous, a nebulous group of cyber-activists, hacked BART's web site over the weekend to protest the cell phone censorship. The action drew a few hundred people, though at times it appeared that media outnumbered activists (and indeed, many people filled both roles). Police ordered protesters to leave after about 20 minutes and BART closed Civic Center station. Activists then dispersed, some marching on Market Street and others protesting at other downtown BART stations. At one point BART had closed all stations between Civic Center and Embarcadero.