I get calls from creditors for my ex-spouse, kids, ex-employees, whatever, they just call whoever they think they can pressure into sending a few bucks or who they can make so miserable they'll turn the screws on the debtor or even pay it off themselves.
I've had debt collectors tell me I was responsible for the debts of my ex-wife. They're just dirtbag scum.
Don’t disagree with your assessment of debt collectors although I would put a property lease holder in a separate class.
When you sign a lease for rent or a loan they always ask you for a reference of a friend and a relative. In case something happens to you so they can contact them.