An undercover police officer, who had been marching with anti-police demonstrators, aims his gun at protesters after some in the crowd attacked him and his partner in Oakland, California December 10, 2014. Police said more than 100 demonstrators marched in Berkeley, California, which has a history of social activism. Under cloudy skies, turnout was smaller than earlier in the week, when demonstrators in the area threw rocks at police and shut down a major freeway. (Photo by Noah Berger/Reuters)

A shop assistant creates a window display in a Next store in central London December 30, 2014. British clothing retailer Next's sales rose 2.9 percent in the run up to Christmas mostly due to online and catalogue purchases, hitting the upper end of its predictions and it said full-year profit would rise by about 11.5 percent. (Photo by Neil Hall/Reuters)

India's Border Security Force (BSF) “Daredevils” motorcycle riders perform during a rehearsal for the Republic Day parade on a foggy winter morning in New Delhi January 8, 2015. India will celebrate its annual Republic Day on January 26. (Photo by Ahmad Masood/Reuters)

Men eat oranges from a push cart along a road as a vehicle travels past them in Karachi January 22, 2015. (Photo by Akhtar Soomro/Reuters)

A girl dances in front of the digital art installation “Light in Dark” created by teamLab, a collaborative of Japanese digital artists, during a special exhibition of “Shake! Art Exhibition! and Learn and Play! teamLab Future Park” at National Museum of Emerging Science and Innovation (or Miraikan) in Tokyo, Japan, 19 January 2015. The exhibition is held through 01 March 2015. (Photo by Kimimasa Mayama/EPA)

Ziripot, a traditional figure stuffed with straw, is helped up during Carnival celebrations in the Navarran village of Lantz, on February 16, 2015. (Photo by Vincent West/Reuters)

An Egyptian Coptic Christian girl carries palm decoration during Palm Sunday inside a church in Old Cairo, Egypt, April 5, 2015. For Christians worldwide, Palm Sunday marks Jesus Christ's entrance into Jerusalem, when his followers laid palm branches in his path, prior to his crucifixion. Western Christian churches and most Orthodox Christian churches follow different calendars and observe Easter on different dates. (Photo by Asmaa Waguih/Reuters)

A boy and a woman run across a railway track as a train approaches in Chengdu, Sichuan province, China, October 8, 2015. Many residents disregard sign prohibiting this kind of illegal crossing and choose to do so to save time, local media reported. (Photo by Hao Fei/Reuters/Western China Metropolis Daily)