A visitor looks at a sculpture entitled “Couple Under an Umbrella, 2013” by artist Ron Mueck during the press day for his exhibition at the Fondation Cartier pour l'art contemporain in Paris April 15, 2013. (Photo by Charles Platiau/Reuters)

Tourists play at a beach covered by a thick layer of green algae on July 3, 2013 in Qingdao, China. A large quantity of non-poisonous green seaweed, enteromorpha prolifera, hit the Qingdao coast in recent days. More than 20,000 tons of such seaweed has been removed from the city's beaches. (Photo by China Foto Press)

An artist from the state of Telangana reacts to the camera as they wait for their turn to perform during a media preview displaying a glimpse of culture of different parts of India, in New Delhi, India, Thursday, January 22, 2015. The tableaux will be part of the Indian Republic Day parade on Jan. 26. (Photo by Altaf Qadri/AP Photo)

New York City policemen tangled with demonstrators at a subway station on the opening day of the New York World's Fair, April 22, 1964. Youths attempted to stall the train, which was headed from the city to the fairgrounds, as a form of protest on behalf of civil rights for blacks. (Photo by Charles Gorry/AP Photo)

Norma Galicia aka “Pirulina” takes part in a demonstration during the commemoration of the International Day for the Elimination of Violence Against Women, in Guatemala City on November 25, 2013. So far this year, 696 women have died due to violent events in Guatemala. (Photo by Johan Ordonez/AFP Photo)

Vehicles clog a highway during a hazy day in Beijing, China, Wednesday, February 26, 2014. Beijing remained cloaked in hazardous white pollution hiding much of its skyline Wednesday, despite the announced closures or production cuts at 147 of the city's industrial plants. (Photo by Ng Han Guan/AP Photo)

Desiree Urban is painted at Columbus Circle as body-painting artists gathered to decorate nude models as part of an event featuring artist Andy Golub, Saturday, July 26, 2014, in New York. Golub says New York was the only city in the country that would allow his inaugural Bodypainting Day. (Photo by John Minchillo/AP Photo)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)