Protesters begin to gather ahead of the UK Student Climate Network's Global Climate Strike at Millbank in London, England on September 20, 2019. (Photo by Gareth Fuller/PA Images via Getty Images)
Naked activists for animal rights, covered in fake blood, perform during a protest against the use of fur and leather, at Catalunya Square in Barcelona, Spain, December 16, 2018. (Photo by Albert Gea/Reuters)
A Palestinian protester uses a sling shot to throw stones towards Israeli security forces during clashes on the Israeli border Eastern Gaza City, Friday, November 6, 2015. (Photo by Adel Hana/AP Photo)
Anti-government protesters react on the grounds of the Mezhyhirya residence of Ukraine's President Viktor Yanukovich in the village Novi Petrivtsi, outside Kiev February 22, 2014. (Photo by Konstantin Chernichkin/Reuters)
A woman reacts as anti-government protesters place a dead body on a stretcher after violence erupted in the Independence Square in Kiev, in this February 20, 2014 file photo. (Photo by Vasily Fedosenko/Reuters)
Demonstrators are seen running for shelter from a protest against plans for new austerity measures October 19, 2011 in Athens, Greece. Greece's largest labor unions have called for a 48-hour strike, while the Socialist government is beginning to push through legislation for cost cutting reforms. (Photo by Milos Bicanski/Getty Images)
People walk past a mural depicting Ulster Volunteer Force gunmen in the mainly protestant area of East Belfast on June 23, 2011 in Northern Ireland. The Short Strand and Newtonards Road areas of East Belfast remained mostly peaceful after Protestant and Catholics groups were involved in a stand-off overnight. (Photo by Peter Macdiarmid/Getty Images)