Students from Langata primary school run past riot police as they protest against a perimeter wall illegally erected by a private developer around their school playground in Kenya's capital Nairobi January 19, 2015. Riot police used teargas to disperse students at a school in Nairobi as the children protested against the potential loss of their playground. The playground was fenced off in December, during the school holidays, by a prominent developer who also claims ownership of the land. The title to the contested site is said to be in the name of Airport View Housing Limited, according to local media, with plans to use the space to build a parking lot for a hotel. (Photo by Thomas Mukoya/Reuters)

Actress Zendaya arrives at the 27th Annual Kids' Choice Awards in Los Angeles, California March 29, 2014. (Photo by Danny Moloshok/Reuters)

Girls, who are part of Afghan Mobile Mini Circus for Children (MMCC), participate in a juggling competition in Kabul, Afghanistan August 12, 2015. The MMCC, founded by David Mason from Denmark, teaches cooperation and creativity to children scarred by years of war in Afghanistan. Despite the dangers, the project has grown so popular that it now runs centres in ten provinces and has hundreds of regular students. The circus makes visits to internally displaced persons' camps, schools, orphanages, and holds annual festivals. The children are taught the skills of juggling clubs, walking on stilts and acrobatics. (Photo by Ahmad Masood/Reuters)

Model Heidi Klum and TV personality Nick Cannon speak onstage during Nickelodeon's 24th Annual Kids' Choice Awards at Galen Center on April 2, 2011 in Los Angeles, California. (Photo by Kevork Djansezian/Getty Images)

A large variety of weapons were for sale at the Washington County Fairgrounds Gun Show that drew thousands of people over the weekend, on March 22, 2013. (Photo by Gary Porter)

Mikhail Kalashnikov, the father of the world's most popular assault rifle, is handed an AK-74 November 23, 2002 in Izhevsk,1000 East km. from Moscow. November 23 marked the 55th anniversary of the release of the first Kalashnikov gun. According to the Moscow-based Center for Analysis of Strategic and Technologies some 70 million to 100 million Kalashnikovs have been built worldwide since 1947, compared about 7 million to Kalashnikov's Western rival the M-16 assault rifles. (Photo by Oleg Nikishin/Getty Images)

Participants play with water guns during the Sinchon Water Gun Festival in Seoul, South Korea, July 9, 2016. (Photo by Kim Hong-Ji/Reuters)