AT&T has acknowledged a significant data breach affecting over 51 million individuals, with personal details such as social security numbers exposed.

The compromised data was found on the dark web, with discrepancies reported regarding the total number of affected customers: 51.2 million according to the Maine AG and 73 million per AT&T's own account.

In response, AT&T has reset account PINs for current customers and is mailing notifications to those impacted.

Security concerns are heightened by the fact that passcodes were stored in a format that was not secure.

Initially, AT&T denied the data was linked to its customers, before admitting the breach.

Affected customers are offered one year of free identity theft protection, despite the data being compromised for an extended period.

AT&T is currently facing legal action for the breach and its delayed disclosure.

A separate incident in March 2023 involved a breach at a third-party vendor, impacting 9 million AT&T wireless customers' network information.