The phone numbers and personal data of over 553 million Facebook users have been published online for free by a user in a low-level hacking forum, according to Business Insider. At least 100 countries are included in this leak, with data from 32 million users in the U.S. and 11 millions users in the UK.

This breach includes phone numbers, Facebook IDs, full names, locations, birthdates, bios, and in some cases email addresses.

Insider reviewed a sample of the leaked data and verified several records by matching known Facebook users’ phone numbers with the IDs listed in the data set. We also verified records by testing email addresses from the data set in Facebook’s password reset feature, which can be used to partially reveal a user’s phone number.

To Business Insider, Alon Gal, CTO of cybercrime intelligence firm Hudson Rock, who first discovered the leaked data on Saturday, said:

“A database of that size containing the private information such as phone numbers of a lot of Facebook’s users would certainly lead to bad actors taking advantage of the data to perform social engineering attacks [or] hacking attempts.”

It’s not the first time Facebook has its users’ data leaked online. In 2020, Mark Zuckerberg’s company was involved in a controversial situation regarding privacy issues and confirmed that thousands of developers had been able to access data from inactive users, which is unexpected behavior.

Before that, there was the Cambridge Analytica controversy, in which the company not only got access to the data of anyone who gave permission to a third-party ‘personality quiz,’ but Facebook allowed the app some access to the data of their friends also.

The company has not addressed this new data leak yet, but it could be the worst leak Facebook’s ever been involved.

This morning, we reported that Apple’s CEO Tim Cook is being interviewed on Monday about the company’s new App Tracking Transparency policies change. Cook will also talk about Parlor and Facebook criticism over these tracking changes. The Apple’s CEO quote couldn’t fit more for the moment:

“Yeah, Kara, I’m not focused on Facebook. So I don’t know.”

FTC: We use income earning auto affiliate links. More.

Check out 9to5Mac on YouTube for more Apple news:

You’re reading 9to5Mac — experts who break news about Apple and its surrounding ecosystem, day after day. Be sure to check out our homepage for all the latest news, and follow 9to5Mac on Twitter, Facebook, and LinkedIn to stay in the loop. Don’t know where to start? Check out our exclusive stories, reviews, how-tos, and subscribe to our YouTube channel

About the Author

José Adorno

Brazilian tech Journalist. Author at 9to5Mac. Previously at tv globo, the main TV broadcaster in Latin America.

Got tips, feedback, or questions?