Last time I was at the SFO AC, they had a problem with their card scanners, so they printed an extra copy of my BP and wrote down the first six digits of my account number.

If a non-active card will get you in, and they aren't really recording account numbers, I wonder if AMEX is giving AA an extra $7 for the first purchase made. They never get one from me, as I use one of my 5% restaurant cards.