How Credit-Card Data Left the House Wirelessly

The biggest known theft of credit-card numbers in history began two summers ago outside a Marshalls discount clothing store near St. Paul, Minn. There, investigators now believe, hackers pointed a telescope-shaped antenna toward the store and used a laptop computer to decode data streaming through the air between hand-held price-checking devices, cash registers and the store's computers. That helped them hack into the central database of Marshalls' parent, TJX Cos. in Framingham, Mass., to repeatedly purloin information about customers. The $17.4-billion retailer's wireless network had less security than many people have on their home networks, and for 18 months the company -- which also owns T.J. Maxx, Home Goods and A.J. Wright -- had no idea what was going on.

Full story at The Wall Street Journal Online.