I have actually done this to somebody
Way, way back in the heady days of dial-up modems and Windows 98, "Some Bloke Who No Longer Exists" knocked together a custom 404 page that included, among the reasons why the page might not be available, "The customer might not have paid their website hosting bill", just to teach a particularly recalcitrant customer a lesson. It worked, alright. They paid up within a matter of minutes.
You probably would not get away with a stunt like that nowadays; broadcasting the fact that somebody owes you money is almost certainly a breach of the GDPR.
Anyway, the moral of the story is: If you want to play Silly Buggers, don't take on an opponent who is a black belt in that sport.
Biting the hand that feeds IT
