Why do people-power movements like Anonymous use the Guy Fawkes mask as an emblem?

I’m going to be very, very busy the net few weeks, so will only check in briefly. But I will check responses to this.

Here’s the history of who Guy Fawkes really was. His likeness is parodied in the grinning black & white mask that Anonymous has adopted as an emblem. Does that history make for a positive emblem for non-violent people-power movements?