Fighters battle in Manhattan's Union Square during a massive pillow fight on April 2, 2011 in New York City. Over 130 cities worldwide are participating in the fourth annual International Pillow Fight Day. (Photo by Mario Tama/Getty Images)

A Somali police officer arrests a suspected rebel member of the al Qaeda-affiliated al Shabaab among beach goers in Mogadishu. Al Shabaab claimed responsibility for today's pre-dawn attack on a Kenyan university campus near the Somali border. The following gallery examines who is al Shabaab. Here: Somali police officer (R) arrests a suspected rebel member (L) of the Al Qaeda-affiliated al Shabaab among beach goers at the Lido beach north of Somalia's capital Mogadishu March 23, 2012. (Photo by Feisal Omar/Reuters)

Uranjargal, a leader of the Mongolian neo-Nazi group Tsagaan Khass, stands next to a statue of Chingunjav, a Mongolian national hero, in Ulan Bator June 22, 2013. The group has rebranded itself as an environmentalist organisation fighting pollution by foreign-owned mines, seeking legitimacy as it sends Swastika-wearing members to check mining permits. Over the past years, ultra-nationalist groups have expanded in the country and among those garnering attention is Tsagaan Khass, which has recently shifted its focus from activities such as attacks on women it accuses of consorting with foreign men to environmental issues, with the stated goal of protecting Mongolia from foreign mining interests. This ultra-nationalist group was founded in the 1990s and currently has 100-plus members. (Photo by Carlos Barria/Reuters)

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)

Members of the organization Witness Against Torture wear orange prison jump suits with handcuffs and a hood over their heads during a demonstration urging the government to close down the detention facility at Guantanamo Bay, in Lafayette Park outside the White House January 11, 2012 in Washington, DC. Protesters carry on a 92-hour vigil in a protest of the 10th anniversary of the arrival of the first group of detainees to arrive at the US military facility (Photo by Astrid Riecken/Getty Images)

Workers hold an 80 Kg Paiche (Arapaima gigas) to return it to a pool at a breeding farm in Nueva Loja, Ecuador, March 25, 2016. (Photo by Guillermo Granja/Reuters)

“One Third” – a project on food waste by an Austrian photography Klaus Pichler. According to a UN study one third of the world's food goes to waste – the largest part thereof in the industrialized nations of the global north. Equally, 925 million people around the world are threatened by starvation. The series “One Third” describes the connection between individual wastage of food and globalized food production.

Photo: Pineapple. Place of production: Guayaquil, Ecuador. Cultivation method: Outdoor plantation • Time of harvest: All- season. Transporting distance: 10.666 km (linear distance) • Means of transportation: Aircraft, truck. Carbon footprint (total) per kg: 11,94 kg • Water requirement (total) per kg: 360 l. Price: 2,10 € / kg. (Photo by Klaus Picher)

A woman carries a piglet as she runs on ice during a running challenge in Changsha, Hunan province February 8, 2015. A total of 20 people participated in the challenge requiring them to choose a pig ranging between 15 kg and 115 kg in weight, and carrying it while running on a 20.15-metre-long ice track. The participants that complete the challenge will be rewarded with the pig they carried, local media reported. (Photo by Darwin Zhou/Reuters)