Cheerleaders wait to perform before the New Year's Day parade in London, Britain January 1, 2017. (Photo by Neil Hall/Reuters)

An undercover police officer, who had been marching with anti-police demonstrators, aims his gun at protesters after some in the crowd attacked him and his partner in Oakland, California December 10, 2014. Police said more than 100 demonstrators marched in Berkeley, California, which has a history of social activism. Under cloudy skies, turnout was smaller than earlier in the week, when demonstrators in the area threw rocks at police and shut down a major freeway. (Photo by Noah Berger/Reuters)

Gelada baboons (Theropithecus gelada) play in their enclosure at the Zoo in Zurich, Switzerland, Wednesday, May 15, 2013. (Photo by Steffen Schmidt/Keystone/AP Photo)

German police officers take pictures as fireworks explode next to the Quadriga sculpture atop the Brandenburg gate during New Year celebrations in Berlin, Germany, January 1, 2017. (Photo by Fabrizio Bensch/Reuters)

Female members of the Chinese People's Liberation Army (PLA) honour guard stand behind a string to ensure that they are in a straight line before a welcoming ceremony for Russian President Vladimir Putin outside the Great Hall of the People in Beijing, China, June 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

An undated handout picture made available on 29 April 2016 by the Toronga Zoo shows a baby echidna making a remarkable recovery after being attacked by chickens in a family's backyard at the Taronga Zoo in Sydney, Australia. (Photo by EPA/Taronga Zoo)

Argentine Juan Manuel Silva and Pablo Sisterna (not pictured) crash in their Mercedes car during the 7th stage of the Dakar Rally from Iquique to Uyuni, January 10, 2015. (Photo by Daniel Rodrigo/Reuters)

The 26th annual Visa Pour l’Image, the “Cannes Film Festival” of photojournalism kicks off, filling the French city of Perpignan with more than 3,000 of the world’s best photojournalists and photo editors, along with agencies from around the world. This year’s Visa Pour l’Image showcases 26 exhibitions around the city. Photo: Christians looting a Muslim shop in the “Combattants” district of Bangui. (Photo by Pierre Terdjman/Paris Match)