Earlier quoted context omitted.
This can be nasty. A friend of me once got a ton of phone calls for a specific realtor. Turns out the realtor made a misprint on their business card. The realtor didn't want to do the expense to print new business cards, so they were just going to give this card to everybody. Could he just forward everybody to them, and maybe fill in their customers on some basic information like opening hours and holidays etc. This…
I recall reading about a local business that lost their phone number of decades to a new hospital that printed a bunch of marketing materials with the wrong number and successfully persuaded the phone company to commandeer the number. Update: I remember now, the phone company gave them the wrong number to begin with. Just a bizarre story all around, and quite cruel to the original business.
It worked as expected on their PSTN and cellular network, but not from any other network.