UPDATED Wednesday 7:40 A.M.: At least six people including five adults and one juvenile were arrested at a protest in downtown Denver on Tuesday night, the Denver Post reported.

UPDATED 2:09 P.M.: Russell Brand, whose recent interview with Jeremy Paxman sparked calls for a "revolution", was spotted at the protest in London.

According to Occupy Wall Street, one of the groups participating in the protest, there has been at least one arrest at the D.C. march. OWS shared a photo of the alleged arrest in a post on their official Twitter account this morning.

Supporters and members of the hacktivist collective Anonymous launched a worldwide protest of governmental corruption on Tuesday, in celebration of Guy Fawkes Day, an annual commemoration of the Gunpowder Plot that is primarily celebrated in the United Kingdom.

The holiday is named for Guy Fawkes, a Catholic terrorist who was arrested by British authorities on Nov. 5, 1605, midway through a plot to blow up the House of Lords and assassinate King James. An anonymous letter-writer tipped off authorities, who were quickly dispatched to the House of Lords. There they found Fawkes preparing to light the fuse to 36 barrels of gunpowder. When asked why he had so much gunpowder with him, Fawkes is said to have replied, “To blow you Scotch beggars back to your native mountains.”

The holiday was initially put into place to honor King James I and shame Catholic dissenters, but as Guardian writer Mark Fletcher notes, it has evolved over the years and Fawkes has gradually been “recast as an anti-authoritarian hero.”

Adoption of the Guy Fawkes masks created for the 2005 action film “V for Vendetta” by the Internet group Anonymous has further contributed to the mythology of Fawkes as a freedom fighter. David Lloyd, who designed the “Vendetta” mask, told IBTimes: “The important thing about that mask is that it’s used on a widespread level by many people who just want to use it as an all-purpose symbol of resistance to tyranny, even of perceived tyranny.”

To coincide with the holiday, Anonymous announced that they would be holding a “Million Mask March” on Tuesday around the globe. A website for the event claims that there are 450 protest locations across the United States and around the world. The protest kicked off in Washington, D.C., but is also scheduled to take place in cities like Amsterdam, Sarajevo, Bangalore, Perth and Reykjavik.

A Facebook page for the event describes it as a “call for Anonymous, WikiLeaks, the Pirate Party, Occupy and Oath Keepers to defend humanity.” The official event description adds: “Remember who your enemies are: Billionaires who own banks and corporations who corrupt politicians who enslave the people in injustice.”

Here are some photos of the protest as it spreads around the globe.