Women take part in Belarus Cup in bodybuilding and fitness in Minsk, October 24, 2015. (Photo by Vasily Fedosenko/Reuters)

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)

Gun enthusiasts look over Smith & Wesson pistols at the NRA Annual Meetings & Exhibits on May 21, 2016 in Louisville, Kentucky. About 80,000 visitors are expected to attend the three-day event. (Photo by Scott Olson/Getty Images)

Clashes break out in the stands during the Euro 2016 Group B soccer match between England and Russia, at the Velodrome stadium in Marseille, France, Saturday, June 11, 2016. (Photo by Thanassis Stavrakis/AP Photo)

Britain Soccer Football, West Ham United vs Manchester United, Barclays Premier League, Old Trafford on May 10, 2016. Police play football with a young West Ham fan before the match. (Photo by Eddie Keogh/Reuters/Livepic)

Darts fan Nigel Panton in fancy dress ahead Day Eight of the William Hill PDC World Darts Championships at Alexandra Palace on December 28, 2014 in London, England. (Photo by Jordan Mansfield/Getty Images)

A rugby fan adjusts his latex mask at the rugby sevens tournament in Hong Kong on March 29, 2014. (Photo by Philippe Lopez/AFP Photo)

Fyn Baily aged eight at the Bloodstock festival on August 13, 2011 in Walton-on-Trent, United Kingdom. Bloodstock is the UK's largest heavy metal festival and features both established and unsigned bands over four days. (Photo by Bethany Clarke/Getty Images)