Most cops are criminals.
Petty criminals, mostly, but still, violating rights is a crime.

Presuming enough men in the crowd, you won't have to worry about protecting yourself, there will be a man around to do it.
But, I still recommend a gun for you so you can protect yourself should one of those men go rogue.

If I don't have the authority to write my rules down and force them onto you, and you don't have the authority to write your rules down and force them onto others, and neither of us can delegate an authority we don't have, where do the cops get their authority?

Cops are satan.™