Ready for the cocktail:

>You walk in the store and are ID'd on camera

>You buy everything and use your credit card, which is linked to your ID, since the checkout has a camera too.

>You use your email once, or your address once, with that same credit card, all connected... now they have your email and home address. You significant other has the same address? Everything is linked.

If you really want to get crazy, you can combine voting records too. Based on primary ballot numbers, you can figure out if someone voted D or R in the primary with an address.

Imagine all the stuff you can get from an email address too..