An Occupy Wall Street protestor is arrested by the police during a march from Zuccotti Park to Union Square on March 24, 2012 in New York City. The Occupy Wall Street movement has seen a resurgence in recent weeks in part due to new protests over the killing of Florida teen Trayvon Martin. (Photo by Andrew Burton/Getty Images)

Police take part in a role play exercise as they clear a protest on top of a train during training on March 6, 2012 in Oxenhope, England. A new team of specialist officers set up to deal with searches and policing at a height, such as on top of a train, undergo training exercise in Oxenhope, West Yorkshire. (Photo by Bethany Clarke/Getty Images)

Firefighters attempt to put out a fire at an abandoned building with the protection of St. Louis City Police in St. Louis, Missouri August 19, 2015. Police fatally shot a black man they say pointed a gun at them, drawing angry crowds and recalling the racial tensions sparked by the killing of an unarmed African-American teen in nearby Ferguson, Missouri, just over a year ago. (Photo by Lawrence Bryant/Reuters)

Emergency services work at the scene of a bus accident on the Kingsway in central London February 2, 2015. A number 91 double-decker bus had its roof ripped off after hitting a tree, causing injury to passengers and passers-by, local media reported. (Photo by Peter Nicholls/Reuters)

“Gangnam Style” star PSY's new music video had been watched more than 10 million times on YouTube less than 24 hours after he unveiled his much-anticipated new dance in Seoul, the website showed Sunday. Photo: PSY performs at his concert “Happening” in Seoul, on April 13, 2013. The South Korean pop star's first new single since his viral hit “Gangnam Style” is stealing attention from inter-Korean tensions. (Photo by Kin Cheung/Associated Press)

Osama bin Laden lookalike Ceara Francisco Helder Braga Fernandes laughs while chatting on the phone in his “Bar do Bin Laden” on April 29, 2014 in Sao Paulo, Brazil. Braga says he was known as the “Beard Man” before 9/11 but became known as a Bin Laden lookalike following the 9/11 attacks. He says he is Christian and continues to play the role to support his business. (Photo by Mario Tama/Getty Images)

A 10 week old stuffed Tiger cub and a Tortoise are displayed in a cabinet at an “Endangered Species” exhibition at London Zoo on September 12, 2011 in London, England. The exhibition is organised by “Operation Charm”, a Metropolitan Police partnership aimed at tackling the illegal trade in endangered wildlife and runs for one month at London Zoo. Items include the tooth of a sperm whale, Ivory carvings, and a stuffed Tiger. (Photo by Dan Kitwood/Getty Images)

Afghan police officers secure a transportation headquarters that was besieged for two days last weekend, on May 14, 2011 in Kandahar, Afghanistan. Taliban gunmen and suicide bombers unleashed a major assault May 7, 2011 on locations in Kandahar that included the governor's compound, the mayor's office, police stations, and an intelligence agency headquarters. (Photo by Majid Saeedi/Getty Images)