A hooded protester throws a petrol bomb to riot policemen during clashes, following a rally marking the 43rd anniversary of a 1973 student uprising against the military dictatorship that was ruling Greece, in Athens, Greece, November 17, 2016. (Photo by Yannis Behrakis/Reuters)

Robot inventor Wu Yulu sits on a rickshaw driven by a robot which he invented in his village in rural Beijing's Tongzhou district, China, 17 November 2016. The 54-year-old Chinese farmer living in rural Beijing's Tongzhou district invented 63 robots in the past 30 years. Wu, who only received primary school education, plans to give up the agricultural work for his robot products. He regularly participates in exhibitions, transfers patent rights and teaches at the university to earn money. (Photo by Wu Hong/EPA)

Kayaks, 7, poses for a picture holding toy gun in a camp where Christians displaced by Islamic State militants are living, in Irbil, Iraq, Friday, December 23, 2016. Iraq’s Christians are marking the holiday in his camp for displaced people with a sense of worry and despair, unable to return to their towns they were forced to flee two years ago by the Islamic State group’s onslaught. (Photo by Manu Brabo/AP Photo)

An Afghan judge hits a woman with a whip in front of a crowd in Ghor province, Afghanistan August 31, 2015. An Afghan man and woman found guilty of adultery received 100 lashes on Monday in front of a crowd who filmed their punishment, TV footage showed. (Photo by Reuters/Pajhwok News Agency)

An aerial view of the Grand Mosque is seen on the second day of Eid al-Adha, during the annual haj pilgrimage in the holy city of Mecca September 25, 2015. (Photo by Ahmad Masood/Reuters)

A police officer removes a reveler from standing on a post as they guard and clear the street of revelers dressed in holiday themed costumes during SantaCon in New York Saturday, December 12, 2015. As thousands of Santa-suited merrymakers prepare to hit the city's streets and bars, organizers of the annual pub crawl say they're taking more steps than ever to deter naughty behavior. (Photo by Andres Kudacki/AP Photo)

Valery Bystritskii, 10, gets a fellow student into a lock at Bunny's Gym in July 2015 in Winchester, Tennessee. (Photo by Mike Saliba/Barcroft USA)

In this July 11, 2016 photo, a young, masked drug trafficker poses for photos holding his guns at a slum in Rio de Janeiro, Brazil. Teenagers openly tote guns while they work as guards, lookouts and distributors for drug lords operating just a few miles from where hundreds of thousands and tourists and athletes will be for the Aug. 5-21 Olympic Games. (Photo by Felipe Dana/AP Photo)