Thomas jumps into the water from a spring board at a public swimming pool in Mengen, Germany, 28 August 2016. (Photo by Thomas Warnack/EPA)

A swimmer disguised as Superman dives into the lake during the 78th “Coupe de Noel” (Christmas cup) swimming race in the Lake Geneva, on December 18, 2016 in Geneva. More than 1800 participants took part in the event, a 12-meter-long swimming off the Geneva's bank in the 7 degrees Celsius cold water. (Photo by Fabrice Coffrini/AFP Photo)

Anti-pollution protesters wearing traditional costumes and contemporary gas masks ride bicycles in the Qingming Grand river park in Kaifeng, Henan Province, China on January 1, 2017. The Beijing Municipal Environmental Protection Bureau extended an “orange alert” for heavy air pollution for three more days. (Photo by SIPA Asia/Rex Features/Shutterstock)

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)

Russian Prime Minister and presidential candidate Vladimir Putin speaks during a rally after Putin claimed victory in the presidential election at the Manezhnya Square March, 4, 2012 in Moscow, Russia. Exit polls showed Putin had over 60 percent of the vote according to state television in an election that has been alleged to be marred by widespread violations. (Photo by Oleg Nikishin/Epsilon/Getty Images)

“Masked gunmen publicly shot dead six suspected collaborators with Israel at a large Gaza City intersection Tuesday, witnesses said. An Associated Press reporter saw a mob surrounding five of the bloodied corpses shortly after the killing”. – Karin Laub via Associated Press

Photo: Palestinian gunmen ride motorcycles as they drag the body of a man, who was suspected of working for Israel, in Gaza City November 20, 2012. (Photo by Suhaib Salem/Reuters)