Online Protests – why do they make Joanna uneasy?

Sticking with a theme I picked up on a few days ago about the responsibility of this website, I cane across a very interesting piece from Joanna Geary reflecting on the downsides of online protest:

The appearance of collective action is remarkably easy online, with many individuals able to contribute in small ways (a retweet, joining a Facebook group, writing a short blog post). But this also means responsibility for this action is fragmented. This puts such action in a strange space where it can wield huge power, but no one has ultimate responsibility for it. So what happens if the consequences of a collective action are severe?