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 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)

Kenyan riot police officers raise batons over a man during a demonstration of Kenya's opposition supporters in Nairobi, on May 16, 2016. Opposition protestors led by former Prime Minister Raila Odinga gathered outside the Indepedent Electoral and Boundaries Comission building to demand the dismissal of IEBC commissioners, after alleged bias towards the ruling Jubillee Alliance Party. (Photo by Carl De Souza/AFP Photo)

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)

Opposition protesters take to the streets of Moscow. Mass meeting in Bolotnaya Square on December 10, 2011 in Moscow, Russia.

Photo by: Stas Sedov and Dmitry Chistoprudov; Source: AirPano

An injured protestor is led away during clashes with police near Tahrir Square on November 23, 2011 in Cairo, Egypt. Thousands of Egyptians are continuing to occupy Tahrir Square after four days of clashes with security forces despite a promise from military leaders to bring forward Presidential elections. (Photo by Peter Macdiarmid/Getty Images)

Riot police hold their weapons during a protest by supporters of Kenyan opposition National Super Alliance (NASA) coalition, along a street in Nairobi, Kenya on October 11, 2017. Opposition leader Raila Odinga, has called for protests this week, reiterated that he would not take part in a re- run of the presidential election on October 26, 2017 if his demands are not met, as Kenya' s Supreme Court last month overturned the August election of President Uhuru Kenyatta citing “irregularities” in the counting of results. (Photo by Thomas Mukoya/Reuters)