Seriously? Imagine the following... Say I'm a naive person and say I go for dinner and pay via credit card. Since there's not much information on there, I thro

Seriously? Imagine the following... Say I'm a naive person and say I go for dinner and pay via credit card. Since there's not much information on there, I throw the receipt away. On the receipt (at least those I get here) is my last name, as well as the 4 last digits of my CC number. Now assume my last name was sufficiently rare in the area for a potential attacker to make sure that this was actually my receipt. Also assume, that I'm an Apple nerd with an iCloud account (which I'm not). Some potential hacker finds my receipt, puts 1 and 1 together and calls Apple and gains complete access using nothing but a receipt with 4 digits and a name on it. Is the restaurant to be hold responsible for it because they printed those 4 digits on the receipt? Hell no! Is Apple responsible for giving access to my account to a complete stranger possessing nothing but a CC receipt? Yes. In this case, Apple is after all responsible for the data loss and their security measures are clearly questionable. One should never use a security key which is obtainable by everybody and his grandma. The last 4 digits of your CC number are not private because the card companies decided that it's secure enough to show them.