I manage rental properties and have noticed a trend among various tenants with a history of paying late or bad credit: They often pay rent using money orders. They do this even though I also accept regular checks (I have never required a cashier's check) or even cash. (And yes, most of them have checking accounts.) This has happened with several unrelated tenants at different properties; the only thing they have had in common is a history of credit problems.
So, is there a reason why people with shaky finances use money orders? My only theory is that they're bad at managing money and know that by putting it in a money order, they prevent themselves from being able to spend it before I come to collect the rent.