These folks did a Carfax, but they were Carfaxing not the stolen VIN, but a legit VIN the thief had copied and then stuck on the car. There's nothing to alert anyone, because you're not using the VIN from the stolen car. The only way you'd know anything was wrong was to track back the chain of title and call every previous owner, and eventually you'll hit one that says "no, you're not buying my car -- it's out in my driveway !".......