Police dressed as civilians use violence to overthrow peaceful protests - provocateur strategy

Quebec police admit going undercover at montebello protests
http://www.youtube.com/watch?v=gAfzUOx53Rg

G20 Police spotted in Black Bloc clothing -Toronto G20
http://www.youtube.com/watch?v=-QD3C7cgpW4

Video Report: Tactics, Agent Provocateurs?/Undercover Police
http://www.youtube.com/watch?v=rUInlsNkebw