I have logged in to my online banking and noticed that PenFed had issued a new account number for my AMEX - but the old card is still valid for some time.
The same has happened to my wife.
They give no explanation - this is just a precautionary measure /etc/etc.
Not that I am worried to much - but am wondering what could have prompted them for such an action (was there any massive data breach? if yes - should it have been disclosed?)