Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

Kazuo Hirai, President and Group CEO of Sony Computer Entertainment America, presents the Playstation Vita at the Sony Playstation media briefing on the eve of the Electronic Entertainment Expo (E3) on June 6, 2011 in Los Angeles, California. More than 45,000 people are expected to attend the annual three-day convention to see the latest games and announcements from the gaming industry. (Photo by David McNew/Getty Images)

A sculpture entitled “Powerless Structures, Fig.101” designed by Danish artist Michael Elmgreen and Norwegian artist Ingar Dragset is unveiled on the Fourth Plinth in Trafalgar Square on February 23, 2012 in London, England. (Photo by Oli Scarff/Getty Images)

An Indian Air Force person walks carrying a Nepalese child, wounded in Saturday's earthquake, to a waiting ambulance as the mother rushes to join after they were evacuated from a remote area at the airport in Kathmandu, Nepal, Monday, April 27, 2015. The death toll from Nepal's earthquake is expected to rise depended largely on the condition of vulnerable mountain villages that rescue workers were still struggling to reach two days after the disaster. (Photo by Altaf Qadri/AP Photo)

A girl rides a donkey as another walks by at the Shawqaba camp for internally displaced people who were forced to leave their villages by the war in Yemen's northwestern province of Hajjah March 12, 2016. In northwest Yemen, one of the poorest countries in the Middle East, about 400 families uprooted by the war have been stuck in the Shawqaba camp in Hajjah province for the past year. Residents live in poorly built huts that protect them neither from summer heat nor winter cold in a camp that lacks the most basic services. (Photo by Abduljabbar Zeyad/Reuters)

Rebel fighters from the Jaish al- Fatah (or Army of Conquest) brigades manoeuver an alleged explosive- rigged make- shift armoured vehicle during a major assault on Syrian government forces West of Aleppo city on October 28, 2016 Syrian opposition fighters launched a major assault on government forces to break a months- long siege of rebel- held neighbourhoods of the battered city of Aleppo. Rebel groups including the powerful Ahrar al- Sham faction and former Al- Qaeda affiliate Fateh al- Sham Front fired waves of rockets into government- held western Aleppo, killing at least 15 civilians, a monitor said. (Photo by Omar Haj Kadour/AFP Photo)

Men are held by Iraqi national security agents, to be interrogated at a checkpoint, as oil fields burn in Qayara, south of Mosul, Iraq, Saturday, November 5, 2016. Islamic State fighters launch counterattacks in the thin strip of territory Iraqi special forces have recaptured in eastern Mosul, highlighting the challenges ahead as the battle moves into more densely populated neighborhoods where coalition air power must be used more selectively. (Photo by Felipe Dana/AP Photo)

Ukrainian law enforcement officers restrain an activist of women's rights group Femen, who holds a protest outside the presidential administration headquarters while marking the International Day for the Elimination of Violence against Women in Kyiv, Ukraine on November 25, 2020. (Photo by Valentyn Ogirenko/Reuters)