Blame the trees for catching fire in a forest fire. People caused the riots, not social media.
Is this specific to social media like Twitter or Facebook? Hardly. As some noted about the almost hysterical coverage of these tools by mainstream media, television news reports and tabloid newspapers arguably do as much to publicize and legitimize that kind of behavior as any social network does.
The difference with Twitter and Facebook is that they are always on, and real-time in a way that even television often isn’t. But the real power comes from the connections that such tools allow between individuals: people who may not even know each other, but become part of a much larger phenomenon via their social connections and their ability to communicate quickly and easily.