The trolls are not the kind to actually attend a convention. No, they are only into disruption. They're waiting for the NYC convention where they can play anarchist games.
They sure sound like DNC delegates to me. Either that, or it's just another batch of paid staffers doing some astroturfing to use up any leftover "primary" campaign funds Kerry can spend until next week.
Of course, it could also be an attempt to distract from Berger the Burglar or that the 9/11 commision (yawn!) report emboldened them.