A young man with the date 25 painted on his face, gives the victory sign in Tahir Square ahead of the first anniversary of the revolution on January 24, 2012 in Cairo, Egypt. (Photo by Jeff J Mitchell/Getty Images)

Riot police scuffle with pro-democracy students after hundreds of protesters stormed into a restricted area at the government headquarters, after a rally ahead of the October 1 “Occupy Central” civil disobedience movement in Hong Kong September 27, 2014. Hong Kong riot police used pepper spray on Saturday to disperse dozens of students who had stormed government headquarters, but an equal number held their ground in protests against Beijing's tightening grip on the city. (Photo by Tyrone Siu/Reuters)

A woman sandboards on the mountain in Wadi el-Rayan Fayoum, Egypt, November 18, 2016. (Photo by Mohamed Abd El Ghany/Reuters)

Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)

In this photo taken in October 1917, provided by Russian State Documentary Film and Photo Archive, a machine gunner looks through a window at his position near the Kremlin in Moscow, Russia. The 1917 Bolshevik Revolution was long before the digital revolution allowed anyone to instantly document events. But the clumsy cameras of the time still caught some images that capture the period's drama. (Photo by Russian State Documentary Film and Photo Archive via AP Photo)

A visitor takes a picture of a display bearing hand prints of war heroes from the War of Resistance against Japan, at Jianchuan Museum Cluster in Anren, Sichuan Province, China, May 13, 2016. Tucked away in southwestern China's Sichuan province, a private collector stands virtually alone in exhibiting relics from the 1966-1976 Cultural Revolution. Monday marks the 50th anniversary of the start of the political movement, with no official commemorations planned. Official records whitewash the details of both periods, but admit that Mao made major mistakes. (Photo by Kim Kyung-Hoon/Reuters)

Kyrgyz Communist supporters gather in front of the Soviet Union founder Vladimir Lenin monument in Bishkek on November 7, 2017, to celebrate the 100th anniversary of The Bolshevik Revolution. (Photo by Vyacheslav Oseledko/AFP Photo)

A girl attends Friday prayers in front of an army tank in Tahrir Square in Cairo February 18, 2011. Five years ago thousands of protesters took to the streets demanding the end of the 30-year reign of President Mubarak as Egypt became the second country to join the Arab Spring. After weeks of clashes, strikes and protests across Egypt, Mubarak resigned on February 11, 2011. (Photo by Suhaib Salem/Reuters)