AT&T is cleaning up the mess after an employee violated the company’s security guidelines. 

In a letter sent to affected customers and obtained by Seeking Alpha, AT&T said that it had determined that in August an employee had wrongfully accessed customer accounts and would  have been able to access customers’ account information, social security number and driver’s license number. 

AT&T confirmed that 1,600 customers were affected by the breach. 

As a result, AT&T is offering customers reversal of any charges that may have resulted from the situation, as well as a year’s worth of free credit monitoring through CSID. 

According to a report from Reuters, about 1,600 customers were affected by the breach. 

When asked about why an incident that happened in August is only now being addressed, AT&T spokesman Mark Siegel responded via email: 

“We take our customers’ privacy very seriously and value the trust they have in us. Unfortunately, we recently learned that one of our employees did not follow our strict privacy rules and inappropriately obtained some customer information. This individual no longer works at AT&T and we are directly contacting the limited number of affected customers.”