A data security breach at Hannaford, an East Coast supermarket chain, has exposed the credit card information of 4.2 million customers and resulted in 1,800 cases of fraud so far, the Boston Globe reports. The breach, which went undetected for three months, is one of the largest ever, the AP notes. Hannaford, which also runs Sweetbay supermarkets, says no names or personal information got out, just account numbers of credit and debit cards.
"We have taken aggressive steps to augment our network security capabilities," Hannaford's CEO said. The breach, which occurred while credit cards were being authorized, affected all of the chain's nearly 300 stores. The company warned customers to check their bank accounts and to be aware of scams involving false investigations.