If this was a person, not a company, this would be called stalking.

Chew on this,

A blog article about the merits of giving store clerks your zip code when they ask for it during a credit care purchase, shows what companies can do with that information. 

According to a recent court case in California  (Pineda v. Williams-Sonoma Stores Inc., Cal. Ct. App., 4th Dist., No. D054355). Giving the zip code allows the store to "enhance" the information they already have about your (your name from the credit card) and determine your home address.

The blog written by Chris Hoofnagle and his description of the facts behind this case…

"Jessica Pineda visited a store in California owned by Williams-Sonoma Stores, Inc. (the Store) and selected an item to purchase. She then went to the cashier to pay for the item with her credit card. The cashier asked for her zip code, but did not tell her the consequences if she declined to provide the information. Believing that she was required to provide her zip code to complete the transaction, Pineda provided the information. The cashier recorded it into the electronic cash register and then completed the transaction. At the end of the transaction, the Store had Pineda's credit card number, name and zip code recorded in its databases.

After acquiring this information, the Store used customized computer software to perform reverse searches from databases that contain millions of names, e-mail addresses, residential telephone numbers and residential addresses, and are indexed in a manner that resembles a reverse telephone book. The Store's software then matched Pineda's now-known name, zip code or other personal information with her previously unknown address, thereby giving the Store access to her name and address."