Alongside my neighbours from the Danforth area, I joined the large march on Saturday afternoon on the first day of the G20 Summit in Toronto. We felt proud to be there alongside over 10,000 other Canadians -- women, unionists, students, teachers, people of all ethnicities and backgrounds -- demonstrating our commitment to peace and social justice. We passed by hundreds and hundreds of police without an incident.

Soon afterwards, while catching a meal on the patio at Fran's Restaurant on College Street, we heard glass breaking on Yonge Street, and saw a mob of about 150 coming around the corner, hurling chairs into windows. Someone threw a bottle through a window showering me in broken glass. What was most striking was that there were not any police in sight.

Evidently this group had started rioting on Queen Street over half an hour earlier -- where the police drove one of their cars into the middle of the group then abandoned it. It was soon set on fire -- making a great photo op.

The group proceeded up Yonge Street smashing windows all the way up Yonge Street, at least eight blocks, without being stopped by police.

There were reported to be 19,000 security people on duty, and a senior officer told me they had 7,000 police.

As an academic and an activist, I have participated in numerous demonstrations in Canada, the United States, Europe and South America, and I have never seen such a dereliction of duty.

Normally, there are buses full of riot police right in the downtown core, ready to move at a moment's notice.

The police knew that they should focus their energies on the Black Bloc, especially so late on Saturday afternoon.

But when the rioters came smashing their way up the main street of Toronto, the police disappeared for half an hour.

It would appear that the security forces allowed this riot to happen in order to justify the $1 billion which appeared to have been wasted on security measures in Huntsville and Toronto.

They must not be allowed to discredit those of us who protested peacefully.

We must hold this government responsible for wasting $1 billion dollars on security measures, and then trying to justify it by allowing people to riot.

David Langille is the executive producer for Poor No More, a feature documentary on Canada's working poor.