Actually they were probably there to throw anyone out that got out of line. You can’t get 300 people together to drink and then just expect the local police department to handle any problems that occur on the taxpayer dollar.I mean you can, but it’s a great way to end up in court or legally liable if anyone dies driving home.

Having bouncers (that’s clearly what this is,) presents a legal defense for liability that shows you made a good faith effort to keep the party in line and avoid having anyone get hurt. That goes a long way towards establishing a legal defense. What if two guys get in a fight? If you don’t have bouncers to break them up, one’s gonna get hurt and he’s suing whoever threw the party.

This is no different from how a successful party bar is run, if anything it sounds like they were being fairly responsible. The biggest issue would be the legalities around booze.