AT&T is warning customers that their personal information might have been breached as part of a scheme to unlock and resell devices.
The company said in a filing to the California Attorney General's office that employees at an unnamed service provider it works with had accessed the personal data of customers including social security numbers and date of birth.
According to a letter the company has sent to customers, the breach occurred earlier this year between April 9 and 21 as three workers pulled the customer data in order to request unlock codes from AT&T which could then be used to remove the device from AT&T's network and allow the device to be resold.
The information was apparently part of a scheme by the group to unlock and resell devices on the AT&T network. The company typically allows users to unlock their devices from its network by entering a code which can be obtained from the company by supplying account information including portions of the customer's social security number.
California law requires companies to issue a public disclosure any time they suffer a breach affecting more than 500 residents, though the company has not said exactly how many people were affected in this incident.
AT&T said that it has snail-mailed letters to the customers whose data was accessed, and is offering to pick up the tab for one year of credit-monitoring services, lest the social security numbers be used to register unauthorized charge accounts.
The company is advising affected users to register for the credit reporting services and change the passcode associated with their accounts.
AT&T's disclosure comes just days after restaurant chain PF Chang's said that it had fallen victim to a breach of employee card data. The company, fearing a breach of its payment system similar to the Target hack, has decided to temporarily revert to the use of carbon paper imprinting for all customer card payments. ®