An activist in a Guy Fawkes mask adjusts a skull and crossbones flag during a demonstration against the Anti-Counterfeiting Trade Agreement (ACTA) on February 25, 2012 in Berlin, Germany. (Photo by Adam Berry/Getty Images)

A student runs for cover as riot police clash with students during a demonstration on February 29, 2012 in Barcelona, Spain. Student associations have called upon 120,000 students to strike in protest against education cuts recently announced by the Catalan government. (Photo by David Ramos/Getty Images)

Activists and supporters of Ukrainian nationalist groups light flares during a rally to mark the third anniversary of the Euromaidan Revolution in downtown Kiev, Ukraine, 21 November 2016. About one thousand activists took park in the rally during which they burned tires on the Independence Square, destroyed the Russian bank Sberbank and broke windows in the office of a Ukrainian politician Viktor Medvedchuk, according to Ukrainian media. (Photo by Roman Pilipey/EPA)

A man lights up his cigarette with the flames of a bus burned by anti-government demonstrators during a protest against the constitutional amendment PEC 55, which limits public spending, in front of Brazil's National Congress in Brasilia, Brazil December 13, 2016. (Photo by Adriano Machado/Reuters)

A Venezuelan Bolivarian National Police officer fires tear gas towards demonstrators during a protest in Caracas, Venezuela, Monday, April 10, 2017. Thousands of people in Venezuela's capital are protesting against the government of President Nicolas Maduro, demanding new elections and vowing to stay in the streets during the usually quiet Easter Week. (Photo by Fernando Llano/AP Photo)

An anti-government protester sits on the ground in front of police during a demonstration in Sarajevo February 6, 2014. Hundreds of people turned out in solidarity in the capital Sarajevo, with teenagers throwing eggs and stones at a government building and fought with police. Four officers were taken to hospital, officials said. (Photo by Dado Ruvic/Reuters)

A protester holds a sign in front of riot policemen during an anti-G20 demonstration through the streets of Nice on November 1, 2011 in Nice, France. Anti-G20 demonstrators are gathered in Nice ahead of the arrival of the world's top economic leaders for the G20 summit in Cannes on November 3rd and 4th. The leaders are expected to debate current issues surrounding the global financial system in the hope of fending off a global recession and finding an answer to the Eurozone crisis. (Photo by Christopher Furlong/Getty Images)