PINs are non-transferrable so even if someone had one that they couldn't use they wouldn't be able to pass it on to you. There is a sticky at the top of this page that explains how PINs and Codes work.
my wife talked to Disney when reserving room and we had a code but they said it was expired. Disney reservations did tell my wife there was "always" a code..is this true???But we have yet to find it!!! Thanks for the info on the pin!!