I've seen a similar program of a grocery store (in my case, Bi Lo) offering discounts in conjunction with Sunoco. Any purchases earn you discounts on gas though, not specific items. Also, for the Bi-Lo card there's no scanning of a drivers license - you just fill out a form (which I always fill out with absolutely bogus info). I actually do that with all the grocery store discount cards for privacy concerns. Ask them if they really need your driver's license or if it's optional. I've got cards from Winn Dixie, Food Lion, Piggly Wiggly, Bi Lo, True Value (not a grocery store but they have a similar discount card program), and several others. Haven't put my real name/address on one yet. Heck most of those stores even have a card at the cash register. Though it won't help for fuel discounts at the pump, just for saving the money you can ask to have them swipe the "store card".
Though to be honest, it's hard to stay private these days. Relational databases today can make so many connections it ain't funny. There's tons of stuff that is public record (which is a good thing, though it has drawbacks), and there are companies out there that specialize in taking public info about everyone and linking/analyzing it so that subscribers can find out anything they want about anyone. Lexis Nexis is one such company. They typically market their database access to law enforcement, but since everything they source from is public record anyways they will sell to private entities as well. They did a demo to our sheriff's department a few years ago and it was unreal the amount of data it can dig up. It could produce graphical trees showing relationships (not blood, but personal) to all sorts of acquantances from varios time periods. For example, they asked our sheriff to give them a name of a person he knew, but not too well. They plugged both names into the system. After some searching it reported that he and the other name were indeed linked - the sheriff's wife had shared an apartment with the woman nearly 30 years ago. It then listed a current address for her, along with a picture of her and her current residence and what type of vehicle she drove.
It's pretty simple how they do it though. For instance, as a county we publish property card information on our website. Lists a property's attributes, including owner, sketches, and any photos we have of it. We also list building permit info. They are perfectly free to download and index that information. Sex offender lists are also published by other agencies. State contractor's licensing is done by the state. Other info by other agencies. Just imagine a huge super computer scouring all that info and linking together every bit of it. And from what I'm seeing, it's private companies that are doing most of that indexing and linking, not the government. Heck selling the government's information back to the government in an organized and indexed form is the primary business of these companies.
