Via Buckdog, the CBC files this:
Quebec provincial police admitted Thursday that their officers disguised themselves as demonstrators during the protest at the North American leaders summit in Montebello.OK. But evidently, at least one of them was a rock collector. And Surete du Quebec lied once already. There's no reason to believe them now.
However, the police force denied allegations its undercover officers were there on Monday to provoke the crowd and instigate violence.