Not only do you come across as a coward (for not showing your face while you protest an issue that you supposedly feel strongly about) and discredit every demonstration that you attend in the process, you demonstrate a laughable lack of understanding about the mask and the person it is based on.
The mask itself is the intellectual property of Time Warner, the company that owns the not-great-but-not-that-bad movie “V For Vendetta“. Every time you buy one of those masks, you give your money to a gigantic multinational corporation, and advertise that movie for their company. You probably also help to give a Chinese kid a job in a sweatshop, because these things are not made in New Jersey, you know.
Also, you should maybe Google the actual person Guy Fawkes, or read the wikipedia page about him: (he tried to blow up up the British Parliament in 1604, failed, was tortured and killed, and his death is celebrated every year on November fifth).
So the mask means the opposite of what you think it means. Not only do you look stupid and cowardly, you are screwing up a perfectly valid demonstration. Stop it.
(Sorry for the typo in the previous incarnation of this post and the unfortunate typo therein)