Book selling giant Barnes & Noble is urging customers to check their bank statements after hackers tampered with PIN pads at dozens of stores, including five here in the city.
According to reports, sources close to the investigation say credit card information was stolen from customers who shopped at the bookstore as recently as last month.
Barnes & Noble is now warning customers to check for unauthorized transactions and to change their personal identification numbers.
It's also working with banks and credit card companies to identify compromised accounts.
The company has disconnected all pin pads in its nearly 700 stores nationwide.
For now, cashiers will have to swipe credit cards on readers directly connected to cash registers.
Any purchases made on the company's website or with Nook devices were not affected.