In an earlier post on May 1 (see below) we identified some of the tactics of the Black Bloc and their potential threat to the G8/G20.
The CBC has now published a short story on the Black Bloc but for more details scan down to May 1 in this blog.
http://www.cbc.ca/canada/toronto/story/2010/06/14/black-bloc.html
Another story identifies some of the groups that will be protesting at the meetings:
http://www.cbc.ca/canada/story/2010/06/04/f-g8-g20-protesters.html