MADISON, Wis. – CUNA Mutual says it is gearing up to go to court on behalf of hundreds of credit unions that say they had damage from a card security breach at a big box retailer. Back in March 2004, B.J.'s Wholesale Club suffered a card security breach that compromised the card security of thousands of customers and left hundreds of credit unions holding the bag and now seems headed to court, according to CUNA Mutual. The credit union insurer says that a survey of its client credit unions has found 300 which suffered losses as a result of the breach and that the total cost to credit unions has topped $5 million, with still more results coming in every day. A key to tracking the damage has been identifying the Visa and MasterCard alert codes (Visa CAMS #026 and MasterCard CAN #MCN22) which are tied to the B.J.'s compromise. This allows credit unions to tie losses they experienced to that specific event, according to Marc Krasnick, senior vice president with insurer. CUNA Mutual has not spoken to B.J.'s about settling the dispute, but Krasnick reported that individual credit unions that have approached the retailer about the damages have been rebuffed. The retailer is already being sued by the $2.1 billion Pennsylvania State Employees Credit Union over losses it incurred in the case.