A man from Dinka tribe holds his AK-47 rifle in front of cows in a Dinka cattle herders camp near Rumbek, capital of the Lakes State in central South Sudan December 14, 2013. (Photo by Goran Tomasevic/Reuters)

Iraqis who have fled fighting between security forces and al-Qaida inspired militants in their hometown of Tal Afar arrive in a car at Germawa camp for displaced Iraqis, in a hot dusty plain in the largely-autonomous Kurdish area of Dahuk, 260 miles (430 kilometers) northwest of Baghdad Tuesday, June 17, 2014. (Photo by AP Photo)

Protest posters are attached to the walls surrounding the “Occupy London” camp outside St. Paul's Cathedral on November 01, 2011 in London, England. The Dean of St. Pauls Cathedral The Very Reverend Graeme Knowles resigned yesterday over the church's handling of the anti-capitalist “Occupy London” demonstration, which continues to occupy the grounds outside the cathedral. (Photo by Dan Kitwood/Getty Images)

Doris Dean of Chicago, Ill., sits with her gun shortly after she won a 50 meter, 40-shot event for women with a perfect 400 score at the National Rifle Association (NRA) matches at Camp Perry, near Toledo, Ohio, September 7, 1941. (Photo by AP Photo/DW)

Children admire the work “Little Lost Boy” by Australian artist Paul Trefry is seen on Tamarama Beach as part of the Sculptures By The Sea outdoor art exhibition on November 10, 2009 in Sydney, Australia. (Photo by Ryan Pierse/Getty Images)

A reveller, covered in mud, chats with friends during the Glastonbury Festival at Worthy Farm in Somerset, Britain, June 26, 2015. The outdoor festival runs from 24 to 29 June. (Photo by Dylan Martinez/Reuters)

An employee of Daikin Industries Ltd works the production line of outdoor air conditioning units at the company's Kusatsu factory in Shiga prefecture, western Japan March 20, 2015. As Japan heads into the season of peak demand for room air-conditioners, Daikin managers have been tasked with figuring out how to boost output by some 20 percent at the 45-year-old Kusatsu plant that six years ago the company had almost given up on as unprofitable. (Photo by Yuya Shino/Reuters)

An Israeli boy swims next to sheep belonging to a Palestinian farmer in the West Bank village of Al-Auja in the Jordan Valley on April 8, 2015 during the Jewish Passover holiday. Thousands of Israelis spent the day outdoors, picnicking and touring the country during the eight-day Passover holiday, which commemorates the Israelites' exodus from Egypt some 3,500 years ago. (Photo by Menahem Kahana/AFP Photo)