ValnaoMoreno Valley, California
An ice pick to the side wall of all their tires would be a fitting punishment. When they call police to complain the cops can then give them parking tickets on top.
Definitely don’t crush a spark plug and throw a piece of it against their window, though. Shattered glass is dangerous.
I’ve tried this and it doesn’t work for shit. Maybe I needed bigger pieces? But it would just bounce off with no damage every time.
“Ninja rocks” is what they called the broken ceramic bits from spark plugs because you can throw a handful of them at a window, and it damages the glass without breaking it. When you do break the glass by hitting it after, it shatters more quietly.