Free-fare movement in Brazil is the spark behind mass uprising
InSerbia News: "The protest was organized by the organization known as the Movimento Passe Livre, or the Free Fare Movement. Founded in 2005 in the southern city of Porte Alegre with the aim of establishing cost-free public transportation, the group’s demonstrations earlier this year just before FIFA’s Confederations Cup are credited with providing the spark for the protests that gripped all of Brazil for several weeks."Police infiltrate using black bloc, stage fights, and engage in vandalism
...Involved in the violence were members of the Black Bloc, an anarchist group based in Brazil, according to police. The same group was blamed for ushering in chaos at another demonstration earlier this month in Rio de Janeiro when a peaceful march by teachers demanding better pay ended violently. The trouble arose after the Black Bloc allegedly became involved.
An undercover police colonel dressed in plainclothes was allegedly attacked by the Black Bloc, but rescued by uniformed officers after they pulled him out of the masked anarchists. The theory that Brazilian police officials infiltrate a rally, blend into the crowd, and incite violence to allow for an official security reaction has been floated before, and this instance adds fuel to that fire.