Here's something I learned from AMEX last week ... if one of your cards gets compromised and you cancel the card, AMEX will continue to allow charges to flow through that old "canceled" number to your newly issued number if those charges are coming from a "trusted recurring entity". I discovered that charges were continuing to flow through a number that I'd canceled due to it being compromised even though I thought it'd been nullified. AMEX explained that their policy is to allow these charges to continue, and it took a number of months before I caught the problem because the charge was coming from a business I continued to have business with. Apparently the person that stole my number had setup a recurring charge with this business as well. To their credit, AMEX removed all of these charges even though they spanned a number of months ... but it caught me completely by surprise that a number I though was canceled was still allowing charges to flow through it.