alphabet + numbers 0-9
Somebody who is so damn desperate and a LOT of time could take weeks putting in random letter and number combinations and finally get one.
It would take thousands of lifetimes to get one number if you're extremely lucky.
Your key does NOT get deactivated. Why everyone thinks it gets deactivated...Quote from FAQSo, no deactivation, just the huge failure for the idiot who gave it away that only one can use it at a time if they are in different private networks.