“(Holmes’) age, the black clothes and gas mask he was wearing, the facts he is white and underground, the facts he is a drifter prone to over-the-top violence, it all fits. Batman features an Occupy-type bad guy and this nut job may have taken it personally.”
Tenuous connection at best. What other kind of clothing would you wear if you wanted move around at night and what else would you wear on your face if you were going to throw tear gas?
That and Black Bloc has never actually gone around shooting people, so saying this is their “tactics” is kind of silly.