Tourist Police sit in the shade on a road leading to the Coptic Cairo area on May 27, 2011 in Cairo, Egypt. Protests in January and February brought an end to 30 years of autocratic rule by President Hosni Mubarak who will now face trial. Food prices have doubled and youth unemployment stands at 30%. Tourism is yet to return to pre-uprising levels. (Photo by Peter Macdiarmid/Getty Images)

Riot police face off with demonstrators at the “Occupy Denver” camp on October 29, 2011 in Denver, Colorado. Following a march by protesters, police moved in on their encampment to tear down recently erected tents. They arrested numerous protesters, pepper-sprayed others and others reportedly fired rubber bullets at the crowd during the confrontation. (Photo by John Moore/Getty Images)

Rescuers search for survivors in the rubble of a collapsed residential building in Makongeni estate in Nairobi December 17, 2014. Three more bodies were recovered on Wednesday night from the building that collapsed in Makongeni estate in Nairobi, raising the death toll to four, Kenya Red Cross has reported. The residential building whose sixth floor was still under construction had allegedly not been cleared for occupation by the Nairobi City County and its owner has been missing since it collapsed. A search and rescue and rescue operation is ongoing for the unknown number of people still trapped under the rubble, Kenya Red Cross also reported. (Photo by Thomas Mukoya/Reuters)

In this May 14, 2016 photo, children wearing their school backpacks climb on a cliff using a bamboo ladder on their way home from school in Zhaojue county, southwest China's Sichuan province. A village in China's mountainous west where schoolchildren must climb an 800-meter (2,625-foot)-high bamboo ladder secured to a sheer cliff face may get a set of steel stairs to improve it's safety. (Photo by Chinatopix via AP Photo)

As part of FLAIR Melbourne – a Flinders Lane art festival – Melbourne’s Lisa Minogue presents stylised photographic portraits of Australian women of colour, their faces painted vibrantly to accentuate their individuality and encourage the viewer to study each face more closely. Minogue asked each woman the same question: “What do the words “coloured girl” mean to you?”. (Photo by Lisa Minogue/The Guardian)

A motorcyclist performs the superman stunt on a highway in Kuala Lumpur, Malaysia, September 14, 2014. Crowds of small motorbikes ridden by racers – or “Mat Rempit”, as they are known in Malaysian slang – face off in impromptu races in the Malaysian capital after dark. The decades-old culture is widely frowned upon by largely conservative Malaysians, who fear its potential to encourage gambling, drug abuse, snatch thefts and sexual promiscuity. (Photo by Olivia Harris/Reuters)

A schoolgirl is soaked with water thrown by an elephant in a preview of the upcoming Songkran Festival celebration, the Thai traditional New Year, also known as the water festival in the ancient world heritage city of Ayutthaya, Thailand, 11 April 2016. The annual elephant Songkran is held to promote the tourism industry prior the three-day Songkran Festival which starts on 13-15 April annually and is celebrated with splashing water and putting powder on each others faces as a symbolic sign of cleansing and washing away the sins from the old year. (Photo by Diego Azubel/EPA)

A driverless vehicle runs at Vanke's Building Research Centre testing area in Dongguan, south China's Guangdong province November 2, 2015. The country's largest property developer, China Vanke, is investing in its own robots to do certain jobs in the face of a labor shortage in the world's most populated country. This driverless car is among the robots that Vanke is aiming to bring in. (Photo by Tyrone Siu/Reuters)