DHS will start swiping the cards in your wallet at the border

According to this Forbs article, DHS is going to start checking your cards at border entry points. They are doing this to find pre-paid / stored value cards which need to be declared like you would cash (you would, right?).

My worry is that this may allow them to capture account numbers and other information from any other cards that they swipe while checking to see which cards meet the criteria.