In your scenario I think you should ask the original owner to return said deposit and refund 28-29 days worth of prepaid rent. There is nothing wrong with collecting rent while not paying mortgage, but collecting rents beyond your ownership and not refunding deposit is crap. I still don’t see your point that the new owners are bad people because they want rent from tenants that live in their property. They should credit them this month’s rent, but starting next month rent should be paid. If the home would have been sold through the short sale process, would this not be the same outcome for the tenants. Why is this scenario any different? If the new owners want the tenants to leave quick, the tenants should be paid a fair amount (cash for keys) to leave quick.