A demonstrator catches fire during clashes with riot police within a protest against Venezuelan President Nicolas Maduro, in Caracas on May 3, 2017. Venezuela's angry opposition rallied Wednesday vowing huge street protests against President Nicolas Maduro's plan to rewrite the constitution and accusing him of dodging elections to cling to power despite deadly unrest. (Photo by Ronaldo Schemidt/AFP Photo)

Demonstrators clash with riot police during a protest against President Sebastian Piñera on October 21, 2019 in Santiago, Chile. President Sebastian Piñera suspended the 3.5% subway fare hike and declared the state of emergency for the first time since the return of democracy in 1990. Protests had begun on Friday and developed into looting and arson, generating chaos in Santiago, Valparaiso and a dozen other cities resulting in at least 8 dead. (Photo by Marcelo Hernandez/Getty Images)

A pro-democracy demonstrator fights with a Soviet soldier on top of a tank parked in front of the Russian Federation building on August 19, 1991, after a coup toppled Soviet President Mikhail Gorbachev. The same day, thousands in Moscow, Leningrad, and other cities answered Russian Republic President Boris Yeltsin's call to raise barricades against tanks and troops. (Dima Tanin/AFP/Getty Images)

Supporters of Venezuela's President Nicolas Maduro take part in a rally in support of the government in Caracas, Venezuela on May 20, 2019. (Photo by Ivan Alvarado/Reuters)

President Barack Obama speaks to the press in the Briefing Room of the White House April 27, 2011 in Washington, DC. US President Barack Obama released a long form version of his birth certificate after extended criticism by those who do not believe he was born in the United States. (Photo by Brendan Smialowski/Getty Images)

Children wave Vietnamese and American flags while waiting for arrival of U.S. President Barack Obama (not pictured) before a welcoming ceremony at the Presidential Palace in Hanoi, Vietnam May 23, 2016. (Photo by Reuters/Kham)

Mongolian President Tsakhiagiin Elbegdorj (C) walks towards the media after casting his vote for the parliamentary elections at a polling station in Ulaanbaatar, Mongolia, June 29, 2016. (Photo by Jason Lee/Reuters)

A photograph of Cuba's former President Fidel Castro decorates a wall inside a state-run market in Havana, March 8, 2016. (Photo by Alexandre Meneghini/Reuters)