T-Mobile Data Breach Could Affect 6 Million Californians

California has issued a consumer alert about a T-Mobile data breach that has affected millions of customers throughout the U.S., including many in California.

The cyberattack, which occurred last year, stole personal information for current, former and prospective T-mobile customers.

California Attorney General Rob Bonta says a recent discovery showed that a "large subset" of that stolen data was up for sale on the dark web.

"Sensitive personal information and private information was compromised as part of that, including social security numbers, dates of birth of almost 54 million people," Bonta said. "There [were] about 6 million Californians who are affected."

Bonta is urging anyone affected by the data breach to take steps to protect themselves from identity theft.

That includes monitoring your credit for suspicious activity and putting a fraud alert on your credit report.