I just read the thread about renting scooters. This is exactly the kind of thing I am talking about.
The complainer said he rented a scooter and had a minimal damage, but that a ship's agent (a local person responsible for interfacing between the port and people on the ship) came onboard the ship and demanded $400 from him or else the police would come aboard and arrest him.
He was on a Costa ship stopped in Cozumel.
Never rent scooters! They are very dangerous (crewmembers are forbidden from renting them) but this extortion scheme is yet another wrinkle I had not heard about before.