The ZIP Code Collection Debate Rages On

Stephens said that unlike swiping your credit card at the cash register, pairing your ZIP code with your name can help "merchants figure out your mailing address, phone number and specific demographic information."

Once a retailer has this information, it can then send you a catalog or even sell your profile to a data broker. It happens all the time, but most people have no idea of the implications of revealing their ZIP code, Stephens said.