Comment Re:Not a chance (Score 1) 631
It is very illegal for a merchant to store your credit card number for more than the 5 seconds it takes to authorize the transaction, unless they implement fairly strong protection to make sure nobody can steal those numbers later. But even if they do this, it is still very illegal for them to try to share those card numbers and what they purchased, which would be necessary for different merchants to "track" your purchases.
You seem to have a pretty good understanding of the topic and I'd like to expand upon it. I've worked with several payment processors and been involved with many systems which handle credit card data and PCI compliance has very a specific definition (expanded, see also) about what card holder data is. Your first and last name, billing address, expiration, last 4 and the card type are not card holder data. Plenty there to "track" legally without touching the PAN (Primary Account Number). That said, I have no desire to see CurrentC implemented.
This doesn't even really touch companies like Acxiom. Here's a little scoop on the whole data broker thing for those unfamiliar with the scope of collection.