Once

we threw rocks into the neighbour's pool because we were bored. It was an above ground pool, so that wasn't really a very good idea. They were big rocks and damaged the pool somehow. They might have even been bricks. All I remember about that was the guy coming out yelling "Eh, la..." followed by a lot of french swearing.

I think I actually got spanked for that. By the way, this didn't happen recently.