Russian police detain a protester at a demonstration against President Vladimir Putin in St.Petersburg, Russia, Saturday, May 5, 2018. (Photo by Dmitri Lovetsky/AP Photo)
Andrea Petkovic of Germany in action against Sara Errani of Italy during day one of the Mutua Madrid Open tennis tournament at the Caja Magica on May 3, 2014 in Madrid, Spain. (Photo by Julian Finney/Getty Images)
An Oakland Raiders cheerleader performs during the second half of an NFL football game against the Pittsburgh Steelers in Oakland, Calif., Sunday, October 27, 2013. (Photo by Marcio Jose Sanchez/AP Photo)
An animal rights activist washes herself with red dye to mimic blood during a protest against the testing of shampoo on animals in Barcelona. April 24, 2012. (Photo by Raul Albaledo/AFP Photo)
An army tank fires during a firefight against militants linked to al Qaeda near the southern Yemeni city of Zinjibar May 30, 2012. (Photo by Reuters/Yemen's Defence Ministry)
A police officer lies on the street after being run over by a bus during a protest against the increase in the price of public transport in San Cristobal, Venezuela March 29, 2016. (Photo by Carlos Eduardo Ramirez/Reuters)
A student protester throws a stone against a riot police vehicle during a demonstration to demand changes in the education system in Santiago, Chile, April 21, 2016. (Photo by Ivan Alvarado/Reuters)
Animal rights activist, stained with fake blood, perform during a protest against the use of animal skins in the clothes and fashion industry, in Madrid, Sunday, December 10, 2017. (Photo by Francisco Seco/AP Photo)