Anti-Heathrow expansion activists walk through the “Grow Heathrow” protest camp in the village of Sipson near to Heathrow Airport, west London Britain December 7, 2015. (Photo by Peter Nicholls/Reuters)

Animal rights groups and PETA stop in front of a Prada store on Rodeo Drive during an anti-fur demonstration urging Black Friday shoppers to stop buying fur-related products on November 25, 2011 in Beverly Hills, California. (Photo by Kevork Djansezian/Getty Images)

Punk protest band p*ssy Riot member Maria Alyokhina is detained by police at a protest in central Moscow February 24, 2014. Russian riot police detained over a hundred protesters, including two members of p*ssy Riot, on Monday at a Moscow courthouse where seven opponents of President Vladimir Putin were jailed from two and a half to four years over a demonstration that turned violent. (Photo by Maxim Shemetov/Reuters)

An anti-government protester sits on the ground in front of police during a demonstration in Sarajevo February 6, 2014. Hundreds of people turned out in solidarity in the capital Sarajevo, with teenagers throwing eggs and stones at a government building and fought with police. Four officers were taken to hospital, officials said. (Photo by Dado Ruvic/Reuters)

Police in riot gear hold back demonstrators against U.S. Republican presidential candidate Donald Trump outside the Hyatt hotel where Trump is set to speak at the California GOP convention in Burlingame, California, U.S., April 29, 2016. (Photo by Noah Berger/Reuters)

Members of the Ukrainian Interior Ministry's special battalion Kiev-1 rescue a hostage, who was detained by a mock terroist, during an anti-terror drill in Kiev, Ukraine, August 28, 2015. (Photo by Valentyn Ogirenko/Reuters)

Chinese special policemen rank in a line of battle during an anti-terror drill at a training base of Chengdu Armed Police Headquarters on September 28, 2005 in Chengdu of Sichuan Province, China. (Photo by China Photos/Getty Images)

The student Patricia Vasconcellos de Almeida, 22, tried to kiss one of the military police who formed a cordon ostensibly in front of the building Fetranspor (Federation of Transport Companies), in Rio de Janeiro, on June 27, 2013. (Photo by Zulmair Rocha/UOL)