Not only does wearing a Guy Fawkes mask at demonstrations give protesters anonymity, it's creates an instant community with other protesters and marks its wearer as a rebel.
This article titled “The V for Vendetta mask: a political sign of the times” was written by Euclides Montes, for guardian.co.uk on Saturday 10th September 2011 13.00 UTC
The now emblematic Guy Fawkes mask, made famous by the film V For Vendetta (somewhat based on the graphic novel of the same name by Alan Moore) has surprisingly become a worldwide bestseller. More than 100,000 masks a year are now being sold. This number seems destined to keep rising, since the accessory has become the en-vogue revolutionary symbol for the younger generation, perhaps even challenging the previous revolutionary iconography of the famous photograph of Che Guevara by Alberto Korda.