South Korean youths dance to electronic music during the Ultra Music Festival Korea at Olympic Stadium on June 10, 2016 in Seoul, South Korea. (Photo by Jean Chung/Getty Images)

A Yemeni soldier, pictured through a vehicle's windscreen, which was damaged by a bullet, gestures out of the window, in Marib, Yemen October 15, 2015. Marib is a city that is heavily armed even by the standards of Yemen, where the ready availability of weapons helped start civil war and is now preventing anyone coming out on top. Yemenis often say there are three guns for every person, a boast that has become an urgent concern in a country where the United Nations says the humanitarian situation is "critical". (Photo by Angus McDowall/Reuters)

Spanish bullfighter Julian Lopez “El Juli” adjusts his montera (bullfighter's hat) before starting a bullfight at the Malagueta bullring in Malaga, southern Spain, April 4, 2015. (Photo by Jon Nazca/Reuters)

A women sits on the south rim of Grand Canyon National Park in northern Arizona, April 12, 2015. (Photo by Jim Urquhart/Reuters)

In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group attack pushers of spice, a synthetic drug, in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)

In this photo taken on Sunday, July 5, 2015, police officers walk along a giant poster to give an improved appearance, in downtown Ufa, Russia. Ufa will host SOC (Shanghai Cooperation Organization) and BRICS (Brazil, Russia, India, China and South Africa) summits July 7 to July 9, 2015. (Photo by Vadim Braydov/AP Photo)

Nora Muaid stands in Zawraa Park on December 2, 2011 in Baghdad, Iraq. The park's 180-foot tall Ferris wheel opened earlier this year and is the second largest in the Middle East. (Photo by Mario Tama/Getty Images)

The MSC Napoli cargo ship lies in a dry dock at Harland and Wolff ship builders as it is dismantled for recycling on April 11, 2008 in Belfast, Northern Ireland. (Photo by Peter Macdiarmid/Getty Images)