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)

An animal rights protester demonstrates for the abolition of bull runs and bullfights, three days before the start of the famous running of the bulls San Fermin festival in Pamplona, northern Spain, July 4, 2015. (Photo by Eloy Alonso/Reuters)

Firefighters attempt to put out a fire at an abandoned building with the protection of St. Louis City Police in St. Louis, Missouri August 19, 2015. Police fatally shot a black man they say pointed a gun at them, drawing angry crowds and recalling the racial tensions sparked by the killing of an unarmed African-American teen in nearby Ferguson, Missouri, just over a year ago. (Photo by Lawrence Bryant/Reuters)

The best man in a wedding party, who all declined to be identified, stands near the bride and groom as he holds an AR-10 rifle he was handed while the party was having their pre-wedding portraits taken on the steps of the capitol before a rally nearby by gun-rights advocates to protest a new expanded gun background check law in Washington state Saturday, December 13, 2014, in Olympia, Wash. The wedding party was not part of the protest, but posed for pictures with it after being handed it by gun activist Brandon Lyons, who said “we've all just broken the law”, by handing the gun over. Saturday's protest was called the “I Will Not Comply” rally, and those attending said they will openly exchange firearms in opposition to the state's new voter-approved universal background check law, Initiative 594. The law, which took effect on December 4, requires background checks on all sales and transfers, including private transactions and many loans and gifts. (Photo by Elaine Thompson/AP Photo)

Protesters dressed as cows march during a demonstration outside of the Wisconsin State Capitol on March 12, 2011 in Madison, Wisconsin. Tens of thousands of protestors staged a massive demonstration outside of the Wisconsin State Capitol one day after Gov. Scott Walker signed his controversial budget repair bill into law.

Flames from a burning barricade lit by pro-democracy protesters is reflected in the windows of a passing bus as passengers watch on during a protest gathering in front of Mong Kok police station on September 22, 2019 in Hong Kong, China. Pro-democracy protesters have continued demonstrations across Hong Kong, calling for the city's Chief Executive Carrie Lam to immediately meet the rest of their demands, including an independent inquiry into police brutality, the retraction of the word “riot” to describe the rallies, and genuine universal suffrage, as the territory faces a leadership crisis. (Photo by Chris McGrath/Getty Images)

American actress Nicola Peltz poses on the red carpet as she arrives for the world premiere of the movie “Transformers 4: Age of Extinction” in Hong Kong Thursday, June 19, 2014. The latest installment in the blockbuster series of “Transformers” films is making its world premier not in the usual entertainment hubs of Los Angeles or New York but in the wealthy Chinese metropolis of Hong Kong, the latest sign of Hollywood's increasing focus on China's booming film market. (Photo by Kin Cheung/AP Photo)

“Strike Through The Mothership”. Every May for the last 3 years I have driven down to Tornado Alley to capture some amazing storms. This supercell held so much promise to drop a tornado but one small shift in the atmosphere and all that it produced was an extreme lightning show. Photo location: Broken Bow, Nebraska. (Photo and caption by Vanessa Neufeld/National Geographic Photo Contest)