Dude, I have had that happen at Death Valley!! Probably wasn't the people you were tailgating with but someone else...or at least I would hope so.
I too had that happen once in B.R. and I learned to always put all of my stuff inside of a vehicle. Atleast there it has a fighting chance to not get stolen.
It's true, the fan took the trombone players slide off his horn and then bent the tubing beyond repair. The man was not arrested or thrown out. Skip did talk to their AD. All band members are ok but it is a dangerous situation with fans pulling and pushing on horns while we are playing. The band member could well have been toothless had he shoved the horn instead of pulling on the slide. For that same reason there are no trombones on the inside of the tunnel for the team to run out after pregame. The players come very close to hitting us when we are out there and members have come off before with a bloody lip. Thanks for your concern and all is well with the band!