"They were not cops ... and, um, so what if they were?"

That didn't take long:

Quebec police admit agents posed as protesters

MONTREAL–With the proof caught on video, Quebec provincial police were forced to admit yesterday that three undercover agents were playing the part of protesters at this week's international summit in Montebello, Que.

Not that they were there to, you know, do anything wrong:

But the Quebec police force denied they were attempting to provoke protesters into violence. Rather, they said the three were planted in the crowd to locate any protesters who were not peacefully demonstrating. Police said the trio's cover was blown when they refused to toss any objects.

Except that...

The three officers, sporting bandannas, showed up on the front lines of a protest at the summit. One carried a large rock.

A large, peaceful rock.