A protester wears a pig mask as he marches through the streets of downtown Vancouver with thousands of people participating in the Occupy Vancouver protest on October 15, 2011 in Vancouver, British Columbia, Canada. Thousands of people are taking to the streets in cities across the world today in demonstrations inspired by the Occupy Wall Street protest in New York City. An estimated 2,000 people participated in the Vancouver occupation. (Photo by Jeff Vinnick/Getty Images)

Climbers ascend the walls of the Westway Climbing Centre on June 15, 2011 in London, England. The Westway indoor climbing centre is located under the A40 flyover in Shepherd's Bush has over 350 climbing routes, some of which rise to over 14 meters. (Photo by Oli Scarff/Getty Images)

A woman on a bicycle rides past the remains of an Audi sedan set afire by an arsonist recently in Zehlendorf district in a street where two more cars were torched on August 23, 2011 in Berlin, Germany. Police have so far made no arrests in a series of arson attacks that have destroyed at least 70 cars within the last week and show no signs of abating. In recent years several hundred cars have been torched annually and police suspect left-wing radicals. The recent series of attacks, averaging about 10 a day, has been particularly severe. (Photo by Sean Gallup/Getty Images)

BERLIN, GERMANY - NOVEMBER 11: Sculptor Oleg Bessonov creates a rosette from clay at the Schlossbauhuette studio where a team of sculptors is creating decorative elements for the facade of the Berliner Schloss city palace on November 11, 2011 in Berlin, Germany. The Berliner Schloss was the residence of the Prussian Kaiser and was among the major architectural landmarks of Berlin until it was heavily damaged by Allied bombing in 1945. The communist authorities of East Berlin demolished the building in the 1950s, and today's Berlin government is pursuing an ambitious project to rebuild the palace according to a design by Italian architect Franco Stella, which will recreate the facade of the building but with a modern interior at a cost of approximately EUR 590 million. The Humboldt Forum, the foundation leading the project, has given the Schlossbauhuette sculptors the formidable task of recreating the hundreds of architectural elements that decorated the facade, and though some original pieces were saved, more often the sculptors have only old black and white photos as reference. (Photo by Sean Gallup/Getty Images)

An inflatable snake hovers during a performance by the French street theater company Plasticiens Volants on September 4, 2011 in Berlin, Germany. The spectale, featuring gigantic flying inflatable fairy-tale creatures and performers on stilts and in costume was a part of celebrations for the 125th anniversary of the Kurfuerstendamm, known locally as the Ku'damm, a shopping boulevard. (Photo by Adam Berry/Getty Images)

A baby Asian elephant, born only two days before, stands next to his mother Nova in its enclosure at Tierpark Berlin Zoo on May 10, 2012 in Berlin, Germany. The male elephant calf, who does not have a name yet, weighs 102kg and is 91cm tall. (Photo by Timur Emek/dapd/Sean Gallup)

Twin baby panthers Remaong and Ferra cling to their basket while being presented to the media at Tierpark Berlin zoo on July 13, 2012 in Berlin, Germany. The two panthers were born in captivity on April 26. (Photo by Sean Gallup)

A picture made available on 16 August 2016 shows a young dare devil motorbike rider, Karmila Purba, 18, reaching for a tip while riding her motorbike inside a barrel locally known as “Tong Setan” or Davil's Barrel, at a traditional night carnival in Deliserdang, North Sumatra, Indonesia, 13 August 2016. (Photo by Dedi Sinuhaji/EPA)