The staff at the computer retailer and service center noticed a file in their server and was concerned that file could contain customers' credit card numbers and personal information.

No one has reported their information stolen yet, but Milwaukee PC isn't taking any chances.

"We think that it is possible that we stopped it before it got out, but to stay on the safe side for our customers, we thought it best to send them a letter,” Troy Salchow, general manager of Milwaukee PC said.

Milwaukee PC sent a warning letter to 65,000 of its customers statewide warning them of the possible security breach. The company is urging customers to place fraud alerts on their credit files, to report any suspicious credit card activity to police and to check their credit reports.

"We are a computer company that does everything that we can to protect our customers' information and I believe it can happen anywhere,” Salchow said.

For more information, call the company's corporate headquarters.at 414-258-2275

You can also file a complaint with the Federal Trade Commission at http://ftc.gov/