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)

Police clash with “Occupy Melbourne” protestors on October 21, 2011 in Melbourne, Australia. Protesters and riot police clashed in Melbourne today after police, acting on a Melbourne City Council eviction order, attempted to break up the crowd of hundreds that had been positioned in City Square for a week. (Photo by Mark Dadswell/Getty Images)

Moscow riot policemen detain an activist during an unauthorized protest anti-Putin opposition rally to defend Article, 31 of the Russian Constitution which guarantees the right of assembly, in Triumfalnaya Square in Central Moscow, Russia, on December, 31, 2011 (Photo by Konstantin Zavrazhin/Getty Images)

Photo by: Sergey A.; Source: LiveJournal

Demonstrators help a fellow protester during clashes with security forces during an opposition rally in Caracas, Venezuela on April 4, 2017. Protesters clashed with police in Venezuela Tuesday as the opposition mobilized against moves to tighten President Nicolas Maduro' s grip on power. Protesters hurled stones at riot police who fired tear gas as they blocked the demonstrators from advancing through central Caracas, where pro- government activists were also planning to march. (Photo by Carlos Garcia Rawlins/Reuters)

A woman cries after riot police dispersed demonstrators during protests to oust Narok county Governor Samuel Tunai in Narok, Kenya, January 26, 2015. At least seven people were injured on Monday in clashes between Kenyan police and protesters from the Maasai ethnic group who accuse a local governor of corrupt handling of tourism funds from the Maasai Mara game reserve, the Kenya Red Cross said. (Photo by Thomas Mukoya/Reuters)

Russian Police detain opposition supporters during a “March of Millions” protest rally against Vladimir Putin's return in Moscow, Russia on May 6, 2012. Over 650 people were arrested including opposition leaders. (Photo by Dmitry Schedrin, Rustem Adagamov, Andrey Stenin)

A demonstrator with face painted in the colours of the Palestinian flag protests outside the Israeli Embassy in west London July 26, 2014. Foreign ministers from the United States, Europe and the Middle East called on Saturday for an extension of the 12-hour ceasefire between Israel and Hamas in the Gaza Strip, French Foreign Minister Laurent Fabius said. (Photo by Luke MacGregor/Reuters)

In this April 4, 2014 file photo, a community policeman kicks a man who they alledge participated in an ambush against them near the town of La Concepcion, Mexico. The vigilante force was set-up by affected communities opposed to the construction of the La Parota hydroelectric dam. Two vigilantes were injured and one died. (Photo by Bernandino Hernandez/AP Photo)