Everyone's looking for a bargain. But do grocery-store club cards cost you more in the long run if information about your shopping habits is shared with other people?

Sue and Mike Rubenstein of Brookhaven, Pa., think those cards help the stores more than they help you.

Like most of us, the Rubensteins want to save money, but they don't like giving up private information to get the lowest prices.

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"Last year, I didn't have to do that, I could just go in there and buy the stuff on sale and use the manufacturers coupon," said Mike Rubenstein. "But now I have to ... they have to know my business."

The transition from regular sale prices for anyone to "sale prices for club members only" has even prompted protests in some markets.

Many stores insist they do not sell or share information, but they certainly store it. And as privacy experts know, what could be done with that information is alarming.

Katherine Albrecht runs a consumer group against loyalty cards. She says the cards are data-collection devices, and that government health agencies have begun efforts to access this data.

"One terrible example I heard recently was it was used in someone's alimony dispute," Albrecht said. "His wife's lawyer used his supermarket club-card information to say he could afford higher alimony because he bought an expensive brand of red wine."

Albrecht says there are other possible scenarios: You could be rejected for health care coverage because you have a heart condition and the insurance company found out from your grocery-store records that you've been filling your cart with potato chips and rich desserts.

The Food Marketing Institute says grocery stores collect the information to better serve customers, to send them coupons and respond to their needs.

Nearly all the major chains in have them but there are still some stores that don't use the club cards.

Walgreens and Trader Joe's don't use club cards. Both stores say they want to offer the same low prices to all their shoppers

The anti-club card movement seems to be gaining some momentum.

One group, www.nocards.org has a Web site that lists stores in your area that use this marketing tool, the private information they ask for and what they say are the disadvantages of club cards.