I recently found my old Peerless handcuffs I would carry when working concert security and a key for them. I used them many times at the Aragon Ballroom in Chicago. There were so many fights in that place it was called "the brawlroom".
If the show was sold out and we would eject 5 or 6 people before the headline act came on, they would sell 5 or 6 more tickets. ;)