New York (NY) - A backup tape of credit cards issued by GE Money has been lost, causing owners of credit card holders from around 230 retailers to be at risk of identity theft.

Data from 650,000 customers have been compromised, according to a GE spokesperson. The backup tape was stored by a company called Iron Mountain, which specializes in data storage and protection. It claims the tape was just "misplaced" and not stolen.

"We also understand the tape was created in such a manner to make unauthorized access extremely unlikely and difficult, even for experts with specialized knowledge and technology," said Iron Mountain in a statement to GE.

Some 150,000 social security numbers were included in the tape. The largest retailer affected was JC Penney. Other stores impacted were not identified. People whose social security numbers were compromised have already been contacted, according to GE, and are being offered 12 months of free credit monitoring services.