SACRAMENTO, Calif. — The Golden 1, a $6 billion credit union, has become the latest CU to have to close member accounts and reissue cards after a card security breach at an area retailer and/or its card processor.

According to media reports, the Secret Service and California authorities are looking in to the case which investigators are calling "sophisticated" and which apparently involved Dollar Tree stores in California and Oregon. The Golden 1 CU CEO Teresa Halleck said that the CU has had to close 800 accounts. Estimates of fraud losses reported to authorities from both states are as high as $500,000. As in similar cases earlier this year and last, it appears that the thieves obtained both card information and personal identification numbers from hacking into either the retailer or its processor's data systems since victims have reported suffering losses from fraudulent ATM transactions.