A Police officer checks a man wearing a carnival costume in Venice, Italy, Sunday, January 31, 2016. Carnival-goers in Venice are being asked by police to momentarily lift their masks as part of new anti-terrorism measures for the annual festivities. Police are also examining backpacks and bags and using metal-detecting wands before revelers are allowed into St. Mark's Square, the heart of the Venetian carnival. (Photo by Luigi Costantini/AP Photo)

A Harley Davidson biker is dressed as Santa Claus as he takes part in a charity ride in Zurich, Switzerland December 6, 2015. (Photo by Arnd Wiegmann/Reuters)

A young Chinese girl dressed in Christmas costume, hugs a pedestrian on a street to celebrate Christmas in Nanjing city, east China's Jiangsu province, 23 December 2015. (Photo by Imaginechina/Splash News)

Iraqi army soldiers fire mortars against the Islamic State militants, at Shahrazad village 2 miles (3 kilometers) east of Mosul, Iraq, Monday, November 14, 2016. A suicide bombing in Iraq targeted the Shiite sacred city of Karbala on Monday, killing at least six civilians, the latest attempt by the Islamic State group to distract from the government forces' offensive on the IS-held northern city of Mosul. (Photo by Hussein Malla/AP Photo)

Let the fun begin. Revellers carry their belongings as they arrive at Worthy Farm in Somerset for the Glastonbury Festival, Britain, June 22, 2016. Around 180,000 are expected to attend. (Photo by Ben Birchall/PA Wire)

Revellers react after falling in the mud at Worthy Farm in Somerset during the Glastonbury Festival, Britain, June 26, 2016. (Photo by Stoyan Nenov/Reuters)

LONDON - JUNE 04: A piece entitled “Entrance into wood” by Elke Krystufek goes on show at The Royal Academy Summer Exhibition on June 4, 2008 in London. In it's 240th year, the exhibition displays a wide range of recent work by both established and emerging artists. 10,000 artists submitted work for selection this year. (Photo by Peter Macdiarmid/Getty Images)