AT&T believes the data, which was stolen in April, is no longer publicly available. Affected current and former customers will be notified by the company but can also check their status online.
The provider says it has reset the passcodes of the current account holders whose data was compromised as it investigates the leak, the latest in a string of telecommunications company data breaches.
Delta Air Lines says it has upgraded its entire fleet to protect the planes against radio interference from wireless signals. The airline said Thursday that it completed upgrading about 190 planes over the summer.
