A dog jumps over an obstacle during the International Agility Riga Cup competition in Riga, Latvia, August 15, 2015. (Photo by Ints Kalnins/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)

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)

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)

Lady Gaga arrives at Nevermind Nightclub on July 11, 2011 in Sydney, Australia. Lady Gaga fans gathered outside two Sydney nightclubs in hopes to catch a glimpse of the singer after she sent a cryptic tweet suggesting her she'd be stopping by the venues. (Photo by Marianna Massey/Getty Images)