The personal information of AT&T might have been compromised when an employee viewed account information without proper authorization, according to a letter the company sent to victims.

Offering a "sincere apology," the telecom company wrote, in a letter signed by Finance Billing Operations Director Michael Chiaramonte, that the accounts were accessed by the employee in August 2014 and that they contained information could have included Social Security numbers and driver's license numbers, as well as Customer Proprietary Network Information (CPNI). That information is “related to the telecommunication services” purchased from the company, the letter explained.

Victims can sign up for complementary credit monitoring services and they are being prompted to change their passcodes. The employee who viewed the information no longer works for AT&T.


UPDATE: Roughly 1,600 individuals were notified by AT&T of the unauthorized access, according to Reuters which spoke to an unnamed individual familiar with the incident.