A poster by street artist Aaron Li-Hill as part of the "Brandalism" project is displayed at a bus stop in Paris, France, November 28, 2015, ahead of the United Nations COP21 Climate Change conference in Paris. Brandalism is a revolt against corporate control of the visual realm. Following on in the guerilla art traditions of the 20th Century and taking inspiration from Agitprop, Situationist and Street Art movements, the Brandalism project sees artists from around the world collaborate to challenge the authority and legitimacy of commercial images within public space and within our culture. (Photo by Benoit Tessier/Reuters)

A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. Image taken by NASA's Hubble Space Telescope. Released September 24, 2015. (Photo by Reuters/NASA/ESA/Hubble Heritage Team)

A couple hugs while standing near a Christmas tree made out of plastic bins and plastic hampers outside the Museum of History in Monterrey, Mexico, December 4, 2015. The humble Christmas tree has a rich history, from evergreen trees used to symbolise eternal life in Ancient Egypt to tree worship among pagan Europeans. The modern version has its origins in Germany, where the song “O Tannenbaum” is still a festive favourite. Today the traditional tree with lights and decorations appears in cities including Washington, Moscow and Beirut. Alternative constructions range from recycled rubbish in Mexico City to old window frames in Rakvere, Estonia. Whatever the shape or size, the message is the same: Merry Christmas. (Photo by Neil Hall/Reuters)

Iraqi pro-government forces fire an anti-tank cannon near al-Sejar village, north-east of Fallujah, on May 25, 2016, as they take part in a major assault to retake the city from the Islamic State (IS) group. Iraqi forces, consisting of special forces, soldiers, police, paramilitary-fighters and pro-government tribesmen, launched a major assault to retake Fallujah, the scene of deadly battles during the US occupation and one of the toughest targets yet in Baghdad's war on the Islamic State group. (Photo by Ahmad Al-Rubaye/AFP Photo)

A student aims a stick of wood at Bolivarian National Police officers during clashes outside the Central University in Caracas, Venezuela, Thursday, June 9, 2016. Students had planned to march from Venezuela's top university to elections headquarters, but hundreds of police in riot gear blocked the way. Students covered their faces with Venezuelan flags and threw bottles, stones and sticks while police lobbed tear gas. (Photo by Fernando Llano/AP Photo)

A Filipino girl is carried along a flooded road in suburban Mandaluyong, east of Manila, Philippines, as monsoon downpours intensify while Typhoon Nepartak exits the country on Friday, July 8, 2016. In the Philippine capital, Manila, and outlying provinces, classes in many schools were suspended and at least six flights, including one scheduled to come from Taiwan, were canceled because of stormy weather and floods following monsoon downpours intensified by the typhoon, Filipino officials said. (Photo by Aaron Favila/AP Photo)

In this September 4, 1963, file photo, a police officer carries off a demonstrator holding a Confederate flag after a group of demonstrators protested enrollment of two African-Americans at Ramsay High School in Birmingham, Ala. The Confederate battle flag has been removed from South Carolina's Statehouse grounds, in the wake of the massacre of nine African-Americans, including a state senator, at an historic black church in Charleston in June 2015. (Photo by AP Photo)

Both men and women dressed as singer Kate Bush from her 1978 video to her song “Wuthering Heights” dance in a brief rehearsal before seeking to create a new world's record for the most people dancing in costume to the song at once at Tempelhofer Feld park on July 16, 2016 in Berlin, Germany. While a precise account was unavailable just after the event, a calculated estimate put the number of dancers at between 400 and 500, well above the previous record set in 2013 in Brighton, UK of 300. (Photo by Sean Gallup/Getty Images)