A demonstrator catches fire after the gas tank of a police motorbike exploded during clashes in a protest against Venezuelan President Nicolas Maduro, in Caracas on May 3, 2017. Venezuela' s angry opposition rallied Wednesday vowing huge street protests against President Nicolas Maduro' s plan to rewrite the constitution and accusing him of dodging elections to cling to power despite deadly unrest. (Photo by Juan Barreto/AFP Photo)

Suspension artist and LUSH Cosmetics employee Alice Newstead inspects shark hooks that she had pierced into her skin during a demonstration against the shark fin trade at a LUSH Cosmetic store on August 24, 2011 in San Francisco, California.

Caroline Wozniacki of Denmark serves in her match against Kaia Kanepi of Estonia during day four of the Toray Pan Pacific Open at Ariake Colosseum on September 28, 2011 in Tokyo, Japan. (Photo by Koji Watanabe/Getty Images)

An activist in a Guy Fawkes mask adjusts a skull and crossbones flag during a demonstration against the Anti-Counterfeiting Trade Agreement (ACTA) on February 25, 2012 in Berlin, Germany. (Photo by Adam Berry/Getty Images)

Colombia midfielder Natalia Gaitan (3) goes up for a header against Mexico midfielder Nayeli Rangel (7) in Moncton, June 9, 2015. (Photo by Matt Kryger/USA TODAY Sports)

People take a photograph at the Kremlin, against the backdrop of the Volga river, in the town of Nizhny Novgorod, Russia, July 10, 2015. Russia will host the 2018 FIFA World Cup soccer tournament. (Photo by Maxim Shemetov/Reuters)

A woman holds her umbrella while walking against strong winds as Typhoon Chan-hom approaches Taiwan, in Taipei, July 10, 2015. (Photo by Pichi Chuang/Reuters)

A Syrian Democratic Forces (SDF) female fighter adjusts a mortar in northern Deir al-Zor province ahead of an offensive against Islamic State militants, Syria February 21, 2017. (Photo by Rodi Said/Reuters)