The black-clad vandals who fanned out across Toronto's downtown are relatively foreign to the city's streets, but their Black Bloc methods and motivations have been deployed around the world for decades.
But the shattered storefronts and graffiti slogans left in their wake do not answer the most fundamental of questions: Who are the ruffians and what do they want?
The individuals who carry on the anarchist Black Bloc tradition today congregate through online forums, newsletters and small conventions. They are yoga teachers, soup-kitchen volunteers, community organizers and university students from Southern Ontario, Quebec and points further afield. They bristle at the anarchist label - they bristle at most things, for that matter - and reject their common portrayal as an ignorant pack of angry young men.
"We don't just crawl up from the sewers from protests," says Chris Bowen, part of the anarchist hip-hop duo Test Their Logik and one of the movement's most visible proponents of property damage. "We are not violent people. I'm filled with love - love for this planet, not for pacifism and the status quo."
It was difficult to see the love in images of smashed Starbucks windows and burning squad cars. Many, including Toronto Police Chief Bill Blair and Mayor David Miller, lamented the violence and promised retribution.
But when your goal is to "smash capitalism," violence takes on a very narrow definition. Mr. Bowen, a yoga teacher by day, insists property damage is necessary to draw the world's eyes.
"When buildings are destroyed and no one is hurt - who cares?" said Mr. Bowen during a protest earlier this week. "It's a broken window, not a life. The violence comes from the companies that are targeted. They are wrecking the environment; they are wrecking lives."
Mr. Bowen was scooped up during mass arrests of demonstrators on Sunday morning, joining the ranks of more than 600 detained by police.
The number of protesters participating in Black Bloc tactics this week were not expected to exceed the roughly 400 who turned out for the 2001 Summit of the Americas held in Quebec City.
"If you look at our movement before and after 9/11, it dwindled," Mr. Bowen said. "People got scared and left."
One of those alleged organizers, Alex Hundert, arrested on charges of conspiracy to commit mischief during an early-morning police raid Saturday, recently wrote a treatise at rabble.ca defending destructive Black Bloc tactics used during the 2010 Winter Olympics.
He claimed that Black Bloc acts as "a wrecking ball" that clears the way for other protest groups to state their various cases. Smashing windows at Hudson's Bay Co., for instance, "actually opened up space for Canadians to stop and think about the colonial history of HBC," Mr. Hundert wrote.
Mr. Hundert is part of a large contingent of demonstrators affiliated with the Kitchener-Waterloo Community Centre for Social Justice.
Other protesters in police custody hail from Montreal, Guelph, Ont., Vancouver and the United States.
"They are your co-workers and neighbours, your teachers or students, your relatives," said one anarchist organizer who asked not to be identified. "If it seems they only appear when an event like the G20 takes place, it's because the rest of the time they are not wearing masks."
Toronto Police have been investigating Black Bloc strategies for months. On Saturday night, Chief Blair vowed to root them out. "There is no sanctuary from responsibility and accountability for their criminal acts," he said.
In a press release Sunday he urged the public to submit any images they have of "the small group of criminals, whose only motivations are violence and destruction, who have appalled those who came to express their views in a peaceful manner."
Many Black Bloc demonstrators arrived in Toronto as part of tight-knit affinity groups - clusters of friends who spread ideas and tactics in small meetings to avoid police detection - to answer a general callout by the Southern Ontario Anarchist Resistance and the Toronto Community Mobilization Network. They've been staying on numerous couches and carpets throughout the city.
"We have friends willing to open their doors here and all across the land," Mr. Bowen said. "They have my back, and I have theirs."
During the destruction on Saturday, affinity groups employed tactics they say were popularized during historical uprisings such as the Boston Tea Party. Dressed in black, affinity groups would dart from within masses of peaceful protesters to smash windows and paint anarchist slogans. Minutes later, they would change into light-coloured garb and rejoin the crowds, relying on the anonymity of the throng for camouflage.
Online explanations of Black Bloc encourage this shape-shifting approach while discouraging violent confrontations with police so that participants can avoid arrest.
These tactics are hardly secret, easily accessed through popular anarchist websites such as crimethinc.com and theanarchistlibrary.org.
Even with hundreds of detained demonstrators, the anarchists insist their movement is snowballing.
"Look here, look at the reaction to austerity measures in Greece, look at the anger surrounding BP in the Gulf," Mr. Bowen said. "The whole global economy is coming down. We are going to kick it until it breaks."
With a report from Colin Freeze