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)

A detained protester escapes from a police truck after riot police released teargas to disperse the #OccupyHarambeeAve demonstration in Kenya's capital Nairobi November 25, 2014. Kenyan police used teargas to disperse demonstrators shouting “President, Stop the killings!” outside President Uhuru Kenyatta's offices on Tuesday, in the protest over 28 people killed in a weekend attack claimed by Islamist militants. (Photo by Thomas Mukoya/Reuters)

Belgian riot police officers are covered by hay and eggs thrown by demonstrators as farmers and dairy farmers from all over Europe take part in a demonstration outside an European Union farm ministers emergency meeting at the EU Council headquarters in Brussels, Belgium, September 7, 2015. Thousands of farmers gathered in the European capital calling for more help with low prices and high costs. (Photo by Jacky Naegelen/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 Israeli policeman prevents a Palestinian man from entering the compound which houses al-Aqsa mosque, known by Muslims as the Noble Sanctuary and by Jews as the Temple Mount, in Jerusalem's Old City September 28, 2015. (Photo by Ammar Awad/Reuters)

Ukrainian police detain activists of women's rights group Femen as they protest against homophobia outside the parliament building in Kiev, Ukraine, November 12, 2015. Femen and gay rights activists are pushing parliament to adopt bills, including one that would ban discrimination in the workplace based on sexuality, which is included in a package of laws to liberalise Ukraine's visa regime with the EU. (Photo by Gleb Garanich/Reuters)

An environmental activist performs during a protest in front of the headquarters of Brazilian mining company Vale SA in downtown Rio de Janeiro, Brazil, November 16, 2015. The collapse of two dams at a Brazilian mine, owned by Vale SA and BHP Billiton Ltd, has cut off drinking water for quarter of a million people and saturated waterways downstream with dense orange sediment that could wreck the ecosystem for years to come. Nine people were killed, 19 are still listed as missing and 500 people were displaced from their homes when the dams burst at an iron ore mine in southeastern Brazil on November 5. (Photo by Sergio Moraes/Reuters)