The theft by hackers of data from at least 45.7 million credit and debit cards of shoppers at nearly 2,500 discount retailers owned by conglomerate TJX, including Marshalls and TJ Maxx, is believed to be the largest such breach of consumer information ever reported. Experts say TJX's disclosures in a regulatory filing revealed security holes that persist at many firms entrusted with consumer data: failure to delete data on customer transactions promptly, and to guard secrets about how such data is protected through encryption.

The figures filed only include transactions in 2003; no estimate was given for information stolen from transactions in 2004. Another 455,000 customers who returned merchandise without receipts had their data stolen, including driver's license numbers.

Main Source: Associated Press