Seattle ? During the recent mad-cow beef recall, one supermarket chain used its “preferred customer” discount cards to identify and warn shoppers who had bought the suspect meat.

In fact, many supermarket chains could do the same thing — but they don’t, largely for fear of being accused of violating customers’ privacy.

“One of our primary objectives is to protect our customers’ privacy, so we don’t want to jeopardize that,” Albertsons spokeswoman Karianne Cole in Boise, Idaho.

Still, she said, the mad-cow recall will probably prompt the chain to take another look at the idea.

At many supermarkets, customers can sign up for an electronically-scanned card that entitles them to discounts. The cards, when combined with the use of bar code scanners at the cash register, give stores a detailed, computerized record of all items bought by each customer, along with the customer’s name, address and phone number.

The data could be used to speed recalls of, say, questionable meat, mislabeled cookies containing peanuts, or other items.

After a Holstein infected with mad cow disease was discovered in Washington state last month, the QFC supermarket chain posted a small sign in its meat departments with a telephone number that cardholders could call to find out whether they had bought any of the 10,400 pounds of beef recalled by the U.S. Department of Agriculture in eight Western states and Guam.

Those who telephoned were asked to supply their card numbers. The store chain then pulled up the customer’s computerized purchase records and told the person whether he or she had bought any meat from the recalled batch.

“We were trying to do the right thing,” said Jeff Burt, vice president of marketing with QFC stores, an 87-store chain in the Pacific Northwest that is an affiliate of Cincinnati-based Kroger Co. “We were trying to help a customer feel just a little bit better.”

Brian Weinstein, 49, displays his preferred customer discount card in front of a QFC grocery story in Mercer Island, Wash. During the recent beef recall related to a Washington case of mad cow disease, the regional grocery chain used its discount cards to advise concerned shoppers whether they might have purchased meat from the infected cow. QFC posted a small notice in its meat departments letting cardholders know they could find out whether they'd bought any of the beef recalled by the U.S. Department of Agriculture. Weinstein bought recalled beef and served it to his family.

In theory, supermarkets could take the initiative and use the discount cards to contact customers first, without waiting to be called.

But the giant Kroger, Safeway and Albertsons chains said they had no plans to take such a step, in light of worries from those who think the cards already give away too much information about customers’ habits.

Kroger has “discussed using the shopper card to alert customers about urgent recalls,” said spokesman Gary Rhodes in Cincinnati. “But we also believe that at this time, the system that’s in place works pretty well.”

Kroger is the parent company of Dillons, which has four stores in Lawrence.

Officials with Albertsons and Safeway said they would track a cardholder’s beef purchases in response to a written request.

Neither invited such requests, however.

One man who unwittingly bought some of the recalled beef at QFC and served it to his family scoffed at the notion that a call from a supermarket would be a violation of his privacy.

“That’s a call to prevent you from poisoning yourself,” said lawyer Brian Weinstein, 49, of Mercer Island, who belatedly tracked his purchase with QFC’s help. “If they’d called me, I’d have said thanks for the public service.”

At least one regional grocery chain — 66-store Wegmans, based in Rochester, N.Y. — has been taking the initiative. It has been using its “Shoppers Club” cards to alert customers to recalls for years, sending out postcards about products.

Wegmans spokeswoman Jo Natale said the company employed the practice for recalls that could involve severe allergic reactions. “We’ve had nothing but positive comments,” Natale said.

The Food and Drug Administration did not immediately return a call for comment on the possibility of using grocery-chain cards to notify consumers about food or drug concerns.

Some customers are troubled by the prospect.

“Sure it would be useful to have someone contact me if I bought something tainted,” Katherine Albrecht, founder of Consumers Against Supermarket Privacy Invasion and Numbering, said from Boston. “But at what cost? A total food-supply surveillance network?”