CDC taps into shopper card data to track food-borne illness

As they scrambled recently to trace the source of a salmonella outbreak that has sickened hundreds around the country, investigators from the Centers for Disease Control and Prevention successfully used a new tool for the first time -- the shopper cards that millions of Americans swipe every time they buy groceries. With permission from the patients, investigators followed the trail of grocery purchases to a Rhode Island company that makes salami, then zeroed in on the pepper used to season the meat. Never before had the CDC successfully mined the mountain of data that supermarket chains compile. Shopper cards have been around for more than a decade, offering customers discounts in exchange for letting supermarkets track their buying habits. The cards are used to build customer loyalty and help stores market their products. Some privacy advocates, though, are troubled. Longtime shopper-card critic Katherine Albrecht, director of a group called Consumers Against Supermarket Privacy Invasion and Numbering, said she worries that the practice could lead to a switch from a voluntary system to mandatory use of such cards. "That sends chills down my spine," she said...read more