Honestly, I think it'd be great if every time a mass celebration breaks out, the city should openly set up and advertise sanctiined celebratory events like this. Buy a couple dead cars from a junkyard and hold a group car flip contest. Grease a bunch of poles and put crash pads around the base. Etc etc. Just turn center city into a big adult playground for a night to direct and contain the energy (and maybe even raise some money for a charity).