We have to stop letting the left frame the debate (right wing terrorists), which causes us to defend why it wouldn’t be right wing terrorism. Instead, we need to be pushing their buttons. Why not OWS? Why not the radical leftists who riot and protest the world trade org, world bank? They destroyed Seattle a few years ago. Why not an organization like weather underground?
I don't think it could be the OWS crowd simply because I believe they would've targeted something different, like BoA headquarters on Federal Street, or something in the Financial District. Killing a bunch of innocent civilians would do the exact opposite of rallying people to their cause.