A policewoman tries to stop an anti-Occupy protester from breaking a police cordon to charge at pro-democracy protesters during a confrontation in Hong Kong October 13, 2014. Hundreds of unidentified people, some wearing masks, tried to break down protest barriers in the heart of Hong Kong's business district on Monday, scuffling with protesters who have occupied the streets for the past two weeks. (Photo by Bobby Yip/Reuters)

Protesters clad in improvised protective gear prepare for a clash with police in central Kiev, Ukraine, Monday, January 20, 2014. After a night of vicious streets battles, anti-government protesters and police clashed anew Monday in the Ukrainian capital Kiev. (Photo by Evgeny Feldman/AP Photo)

Rio de Janeiro's state military policemen aim their guns during a violent protest in a favela next to Copacabana, Rio de Janeiro on April 22, 2014. Violent protests broke out in Rio's landmark beachfront district, Copacabana, following the death of a resident last weekend during clashes with the Army in a nearby favela. (Photo by Christophe Simon/AFP Photo)

Anti-nuclear activists demonstrate during a “Say to Goodbye to Nuclear Energy” protest on September 11, 2011 in Kobe, Japan. Japan is marking sixth months since a magnitude 9.0 earthquake struck Japan offshore on March 11 at 2:46pm local time, triggering a tsunami wave of up to ten metres which engulfed large parts of north-eastern Japan and also damaged the Fukushima nuclear plant, causing the worst nuclear crisis in decades. The current number of dead and missing is reportedly estimated to be 22,900. (Photo by Buddhika Weerasinghe/Getty Images)

Italian police officers carry away a FEMEN activist during a protest in St. Peter's Square at the Vatican, Friday, November 14, 2014. Members of the Ukrainian feminist group Femen staged a protest against the upcoming visit of Pope Francis at the European Parliament and Council. (Photo by AP Photo)

Paint splattered police officers look on during clashes outside Top Shop on Oxford Street, during marches in protest at government cuts on March 26, 2011 in London, England. Thousands are taking part in the Trades Union Congress (TUC) organised march to Hyde Park where a rally will take place. Police say they are deploying 4500 officers. (Photo by Dan Kitwood/Getty Images)

“Belarus riot police detained scores of demonstrators at a protest rally against President Alexander Lukashenko. Rallies against Lukashenko's rule are rare in the tightly-policed ex-Soviet republic, but protest calls on social networking sites have multiplied in recent weeks as a severe currency crisis has brought economic hardship. Demonstrators gathered peacefully, simply applauding in a coordinated act of protest”. – Af.Reuters.com (Photo by Anton Motolko; Belarus, Minsk; June 22, 2011)

A protestor performs outside the parliament during a demonstration against austerity measures announced by the Spanish government in Madrid, Spain on September 29, 2012. (Photo by Andres Kudacki/Associated Press)