Inger Utke, left, takes a selfie with Edwin Galarza, dressed as a “Star Wars” themed dinosaur, during Preview Night at Comic-Con International held at the San Diego Convention Center, Wednesday, July 20, 2016, in San Diego. (Photo by Denis Poroy/Invision/AP Photo)

Children residents take a selfie as they wait for the police to dance, an unconventional approach to connect the police with the community in rough neighbourhoods, as part of the “Tirando Barrio” (Marking territory) programme in Saltillo, Northern Mexico September 9, 2016. T-Shirt reads “Street Dancers”. (Photo by Daniel Becerril/Reuters)

People take part in a Halloween street party at Lan Kwai Fong on October 31, 2016 in Hong Kong. Halloween, a contraction of All Hallows' Evening, falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Lam Yik Fei/Getty Images)

Members of the Oath Keepers and general public return fire during a simulated attack as they take part in a tactical training session in northern Idaho, U.S. October 1, 2016. In April 2015 Reuters photographer Jim Urquhart was assigned to cover the Oath Keepers during a tour of the Sugar Pine gold mine in Oregon after the group of former cops, military, firefighters and other first responders had risen to prominence during a standoff in Nevada over land rights. (Photo by Jim Urquhart/Reuters)

Iraqi rapid response forces take a selfie picture outside a hospital damaged by clashes during a battle between Iraqi forces and Islamic State militants in the Wahda district of eastern Mosul, Iraq, January 8, 2017. (Photo by Alaa Al-Marjani/Reuters)

A dressed up participant without trousers takes part in the 2017 No Pants Subway Ride in New York, the United States, on January 8, 2017. The event, which first took place in New York in 2002, has become a yearly event attended by people in more than 60 cities across the globe. (Photo by Zou Zheng/Xinhua/Sipa USA)

Participants wearing historical attire compete on historical high wheel Penny Farthing bicycles in the traditional 'One Mile Race' at Letna Park in Prague, Czech Republic, November 7, 2015. The meeting of Penny Farthing bicycles is taking place for the 22th time. (Photo by Filip Singer/EPA)

Competitors take part in the Christmas Really Wild Mud Run on a 4.6 miles course across undulating farm land at Celtic Camping, St David's, Pembrokeshire, Wales, December 12, 2015. (Photo by Rebecca Naden/Reuters)