An injured fan is helped by a riot policeman during clashes between Red Star Belgrade and Partizan Belgrade fans in the stadium before the teams' Serbian Superliga soccer match in Belgrade, April 25, 2015. Serbian league leaders Partizan Belgrade held champions and bitter city foes Red Star to a 0-0 draw in a derby match marred by bad crowd trouble before kickoff on Saturday. The start was delayed for 45 minutes after home Red Star supporters pelted riot police with seats and flares, forcing officers to retreat from the north tier that houses the club's diehard fans. (Photo by Marko Djurica/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)

Russia's Alexandra Stepanova and Ivan Bukin perform during the ice dance free dance program at the Rostelecom Cup ISU Grand Prix of Figure Skating in Moscow November 15, 2014. (Photo by Grigory Dukor/Reuters)

“Aquarium or Akvarium (Russian: Аквариум) is a Russian rock group, formed in Leningrad in 1972 by Boris Grebenshchikov (Борис Гребенщиков), then a student of Applied Mathematics at Leningrad State University, and Anatoly (George) Gunitsky, then a playwright and absurdist poet”. – Wikipedia

Flashmob: Water Battle on All-Russian Exhibition Center in Moscow, Russia, on August 5, 2012. (Photo by Lilja Dal)

Paramilitary policemen carry seized crystal meth at Boshe village, Lufeng, Guangdong province, December 29, 2013. Police in the southern Chinese province of Guangdong have seized nearly three tonnes of the drug crystal methamphetamine and arrested 182 people in raids on a village notorious for producing narcotics. (Photo by Reuters/Stringer)

A security exercise takes place along the River Thames on January 19, 2012 in London, England. The exercise including around 44 police officers, 94 military personnel, 15 boats and a Royal Navy Lynx helicopter was conducted by both the Metropolitan Police and the Royal Marines and designed to test their joint capability ahead of the 2012 London Olympic Games. (Photo by Dan Kitwood/Getty Images)