Dan McManus and his service dog Shadow hang glide together outside Salt Lake City, Utah, July 22, 2013. McManus suffers from anxiety and Shadow's presence and companionship help him to manage the symptoms. The two have been flying together for about nine years with a specially made harness for Shadow. (Photo by Jim Urquhart/Reuters)

Mariusz Zbigniew Pudzianowski of Poland leads a match of the 2005 World's Strongest Man Competition at Wuhou Temple on September 27, 2005 in Chengdu of Sichuan Province, southwest China. (Photo by China Photos/Getty Images)

A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)

Riot police walk in the street as a couple kiss on June 15, 2011 in Vancouver, Canada. Vancouver broke out in riots after their hockey team the Vancouver Canucks lost in Game Seven of the Stanley Cup Finals. (Photo by Rich Lam/Getty Images)

Police academy graduates march during their graduation ceremony in Islamabad, Pakistan May 18, 2015. Out of the 408 graduating officers, 76 female officers were inducted into the Pakistan police force, according to the police force. (Photo by Caren Firouz/Reuters)

A member of the Community Police of the FUSDEG (United Front for the Security and Development of the State of Guerrero) poses with a weapon during events to mark the first anniversary of the force's operations in Ocotito, January 23, 2015. Based on the traditional indigenous justice system, the Community Police is made up of volunteers from different communities of Guerrero, and was created in response to the spate of violence in several locations in the state. (Photo by Jorge Dan Lopez/Reuters)

An injured supporter of Kenyan opposition leader Raila Odinga receives assistance in Nairobi, Kenya on November 17, 2017. Kenyan police have used tear gas and water cannons to disperse supporters of opposition leader Raila Odinga who are trying to gather near the country's main airport and Uhuru park to welcome him back from an overseas trip. (Photo by Baz Ratner/Reuters)

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)