Not going to happen and not with that many people. It would be a nightmare in court. They'd have to also show that the people involved were actually part of the game and not in some way just at the store for unrelated reasons. Possible but highly unlikely. Would have to have security tapes that were open and shut and actually use those. Also highly unlikely without the help of some high pressure interrogation and confession of the suspect. What can happen and what does happen are always different things. In theory you can get a ticket for going 56 in a 55mph zone. Generally not something to worry about. Not saying impossible and not saying police don't do that but the risk should not be overstated.
You may have forgotten the "flash mob" craze, when people were sometimes rounded up en masse and prosecuted. This also happens when people get rowdy at bars, concerts, parades, political rallies, etc... It's a thing.
The ones arrested that have the means would hire private lawyers and receive deferred prosecution agreements or simply charges dropped.
The ones without the means would be assigned public defenders who would give them 1 hour of time every 2 weeks, just enough to wear them out and accept a plea deal in lieu of going to court.
The 1% that didn't have the means but fought anyways would go to court/trial, and would also have charges dropped before it went that far.
