Get a phony check in the mail? Don't toss it - try cashing it..

 

Combs deposited the fake check as a joke, not expecting it to clear. 

Surprisingly, due to a series of banking errors, the check was processed, and the funds were credited to his account ten days later.
Combs became obsessed with monitoring his bank account, checking it every ten minutes to see if the money was still there. He did not spend any of the money. Eventually, he had the bank issue a cashier's check for the same amount, which he placed in a safe deposit box.

The rest of his story is here. 

Well played, Mr. Combs...