Black bloc flags left on Spadina Ave. on Saturday. (Jennifer Hollett/CBC)

By Jennifer Hollett, CBC News

The Black Bloc, the Black Bloc, the Black Bloc.

G20 is the trop trend on Twitter in Canada right now, followed by the Black Bloc.

@oliviachow Black Bloc pp have nothing in common with the peaceful rally. All they are doing is to justify huge security spending. #G20

@cody_dodd In an instant, a few dozen in the 'black bloc' delegitimize every real message & legitimize police authoritarianism. Professional thugs 

@mcleangreaves

on behalf of African-Canadians everywhere I would like to point out not one member of the Black Bloc who trashed #G20 is actually black.

And it is being stressed the Black Bloc is a tactic, not a group. I'd say it's fair to say it's both.

The Black Bloc is not new to the G20 protests, the tactic has been around for decades. There's even a Wikipedia entry. How it works: wear black. Black t-shirts, shorts, hoodies, scarfs, flags, and balaclavas. Show up at a protest, attack symbols of capitalism: stores, banks, police cars. When police respond, lose the black clothing and blend in.

As for if they're a group or not, protesters using a Black Bloc strategy work together. Media and other protesters kept an eye on them yesterday as they marched in a group in the protest. Take for example another tactic/group, far more fun, the radical cheerleaders. It's a type of activism, that anyone can use, but activists organize in groups.

So, the Black Bloc is a tactic that involves wearing black and destroying things, used by a group of like minded anti-capitalist protesters.

Related video: The Black Bloc

For more:

The Toronto Star - Behind the Black Bloc mob

The Globe and Mail - Black Bloc strategy has been used for decades