Hackers have stolen credit card information at 63 Barnes & Noble stores around the country. Barnes & Noble does not know how many cardholders have been affected.
The company found the data break around September 14 but waited to release the information so the F.B.I. could investigate who was behind the attacks.
The hackers stole information by breaking into keyboards in front of registers where customers swipe their credit cards and enter their PIN. Some credit card information has been used for some unauthorized purchases. The company said internal systems were not breached. Since this was encrypted information, the law does not require Barnes & Noble to tell customers about the breach.
Barnes & Noble disabled all 7,000 PIN devices at its nearly 700 consumer stores at the time it found the data break. The affected stores were in Florida, New Jersey, California, Connecticut, New York, Rhode Island, Massachusetts, Illinois and Pennsylvania.
Customers who swiped a debit or credit card at an affected store should be sure to review the account for unusual activity. Those customers should also change the PIN on their debit card.