Earlier this August, T-Mobile publicly announced a data breach that leaked over 40 million customer accounts that included social security numbers date of birth, first and last names, and driver's license / ID numbers of existing customers, customers who no longer use the service, and potential customers. The announcement from T-Mobile was published almost 2 days after the stolen information was listed for sale in the cybercrime networks.

T-Mobile mentioned in their statement of a "highly sophisticated" attack on their corporate network caused the data breech.

“Our preliminary analysis is that approximately 7.8 million current T-Mobile postpaid customer accounts’ information appears to be contained in the stolen files, as well as just over 40 million records of former or prospective customers who had previously applied for credit with T-Mobile,” they mentioned on T-Mobile.com