One day around midnight, the people upstairs were having way too loud a party. We tried the universal keep it down signal of pounding on the ceiling with a broom-handle - to no avail. So I got dressed, went up the stairs, and knocked. "Hey, could you guys keep it down? We're trying to sleep downstairs." And the guy and shoves me into the balcony rail, so I'm bent backwards over it. A couple others came out and pulled him off, and I ran for the stairs.
Ever since, I've been reluctant to confront loud neighbors.
Which is why I'm sitting here typing instead of getting dressed to go out onto our back balcony so I can suggest to the people on the balcony next door that, while it's doubtless my fault for trying to sleep with my window open on a hot muggy night, I'd appreciate it they could hold their conversation at a volume that didn't wake me up. It being midnight and all that.
(I'd call the police if it were amplified noise; as it is, I doubt a cop standing in front of their house would hear anything; certainly nothing that would seem loud from there. It's really all about proximity. Not that there aren't maybe a dozen other neighbors who'd be having the same problem if they have their windows open. But I may be peculiar for refusing on principle to install my air-conditioner in May. If they don't pipe down soon, I probably will just give up and install my A/C.)