Protesters clad in improvised protective gear prepare for a clash with police in central Kiev, Ukraine, Monday, January 20, 2014. After a night of vicious streets battles, anti-government protesters and police clashed anew Monday in the Ukrainian capital Kiev. (Photo by Evgeny Feldman/AP Photo)

Israeli police officers confront demonstrators as Israelis protest against rising housing prices and social inequalities on July 30, 2011 in Tel Aviv, Israel. Tens of thousands of Israelis took to the streets in 10 cities across the country to protest against the high cost of living, including more than 50,000 in downtown Tel Aviv. The demonstrators rallied in support of hundreds of people who have set up protest camps against the government's economic and social policies. (Photo by Uriel Sinai/Getty Images)

British Gas engineer Martin Caulfield, 69, services and cleans a gas lamp in front of Big Ben on October 31, 2011 in London, England. Caulfield has been looking after the traditional lights since 1982. There are still around 1600 left in the capital. (Photo by Matthew Lloyd/Getty Images)

The space shuttle Endeavour is transported to the California Science Center in Exposition Park from Los Angeles International Airport (LAX) in Los Angeles, California. (Photo by Kevork Djansezian)

A female street art collective has set a new Guinness World Record to create the largest spray-painted mural by multiple artists. Over 100 international female street artists came together to create the continuous mural in south London’s Leake Street Tunnel, made famous by Banksy, on March 8, 2014. The record was broken as part of all-female street art event Femme Fierce, the largest of its kind in the UK, which aims to celebrate women street artists across the world. Photo: Zabou's witty graffiti. (Photo by Dez Mighty/Susan Mackey)

Supermodel Iman (center) introduces her husband David Bowie (L) to Rihanna (R) at the DKMS' 5th Annual Gala: Linked Against Leukemia honoring Rihanna & Michael Clinton hosted by Katharina Harf at Cipriani Wall Street on April 28, 2011 in New York City. (Photo by Andrew H. Walker/Getty Images for DKMS)

“Gangnam Style” star PSY's new music video had been watched more than 10 million times on YouTube less than 24 hours after he unveiled his much-anticipated new dance in Seoul, the website showed Sunday. Photo: PSY performs at his concert “Happening” in Seoul, on April 13, 2013. The South Korean pop star's first new single since his viral hit “Gangnam Style” is stealing attention from inter-Korean tensions. (Photo by Kin Cheung/Associated Press)

Members of South Korean girl group Gfriend rehearse in Seoul December 23, 2014. Thousands of Korean children dream of becoming household names like rapper Psy, whose 2012 “Gangnam Style” video was a global YouTube hit, often putting up with punishing schedules in the hope of one day making it big in the music industry. A recent survey of pre-teens showed that 21 percent of respondents wanted to be K-pop (Korean pop) stars when they grow up, the most popular career choice. (Photo by Kim Hong-Ji/Reuters)