A boy tumbles as he plays soccer on the streets of the Khayelitsha township in Cape Town, December 3, 2009. (Photo by Kai Pfaffenbach/Reuters)

A woman rides a custom bike during "Bike Kill 12" in the Brooklyn borough of New York City, October 31, 2015. "Bike Kill" is an annual gathering of builders and riders of home-made bicycles that culminates in a tall bike jousting competition. (Photo by Stephanie Keith/Reuters)

Men sleep at a 24-hour McDonald's restaurant in Hong Kong, China November 10, 2015. A large number of homeless people sleeping on the street has long been been a problem in Hong Kong mainly due to its high rent and soaring property. In recent years, McDonald's 24-hour fast food shops opening all over the city have become popular alternatives for people, know as McRefugees or McSleepers, to spend the night in a safer and more comfortable way than on the street. (Photo by Tyrone Siu/Reuters)

A tribesman loyal to the Houthi movement carries his rifle as he leaves a gathering held to show support for the group, in Yemen's capital Sanaa December 15, 2015. (Photo by Khaled Abdullah/Reuters)

Dancers from the Philadelphia Ballet perform for Pope Francis (R) as he attends the Festival of Families rally in Philadelphia, Pennsylvania September 26, 2015. (Photo by Brian Snyder/Reuters)

An officer of a Libyan anti-illegal immigrants unit conducts an early morning raid on migrants at hideout in Tripoli, Libya October 13, 2015. Libyan security forces charged with curbing illegal migration raided a hide-out for illegal migrants in Tripoli on Tuesday. (Photo by Hani Amara/Reuters)

A visiitor bungee jumps during an outdoor festival to celebrate German Unity Day on the 21st anniversary of German reunification on October 3, 2011 in Berlin, Germany. German Unity Day is a national holiday and marks the day West Germany and East Germany were reunited in 1990 following the collapse of the Iron Curtain. (Photo by Adam Berry/Getty Images)

Revellers take part in an annual block party before Carnival in downtown Rio de Janeiro, Brazil, January 16, 2016. The Rio de Janeiro Carnival will be held from February 5 to February 9. (Photo by Pilar Olivares/Reuters)