FILE - In this Jan. 18, 2008 file photo, a customer signs his credit card receipt at a Target store in Tallahassee, Fla. The U.S. is the juiciest target for hackers hunting credit card information. And experts say incidents like the recent data theft at Target's stores will get worse before they get better. That's in part because U.S. credit and debit cards rely on an easy-to-copy magnetic strip on the back of the card, which stores account information using the same technology as cassette tapes. The breach that exposed the credit card and debit card information of as many as 40 million Target customers who swiped their cards between Nov. 27 and Dec. 15 is still under investigation. (AP Photo/Phil Coale, File)