Military & Defense

Facebook just announced it was hacked, and almost 50 million users have been affected

By Rob Price
Mark Zuckerberg
Facebook CEO Mark Zuckerberg. Getty
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A hacker gained access to nearly 50 million Facebook user accounts by exploiting a weakness in the social network's systems, Facebook said on Friday.

News of the cyber attack — which appears to be one of the most significant in Facebook's history — sent shares of the company down roughly 3% in midday trading on Friday, adding to the pile of woes currently weighing on the company.

Facebook CEO Mark Zuckerberg hosted a conference call with journalists shortly after the news was announced, underscoring the severity of the situation. 

"We do not yet know whether these accounts were misused but we are continuing to look into this and will update when we learn more," Zuckerberg said in a blog post published on Friday.

The Silicon Valley tech firm said it discovered on Tuesday that an unknown attacker, or attackers, had taken advantage of a security flaw to take over users' accounts. The flaw was related to the "View As" feature that lets people see what their own profile looks like through the eyes of another user, Facebook explained. 

"This allowed them to steal Facebook access tokens which they could then use to take over people’s accounts," Facebook's VP of Product Management Guy Rosen wrote in a separate blog post.

"Access tokens are the equivalent of digital keys that keep people logged in to Facebook so they don’t need to re-enter their password every time they use the app."

Facebook says it's not yet clear who is behind the attack.

On the conference call, Rosen said that there was no evidence that users' private messages had been compromised, but cautioned that that could change as the process continues. It's also not clear on what grounds people were targered, or why.

The revelation comes a day after a famous Taiwanese hacker publicly declared plans to delete Zuckerberg's Facebook account and to livestream the feat. Facebook representatives said on the conference call that they did not believe the cyber attack was related to the Tawainese hacker.

Do you work at Facebook? Got a tip? Contact this reporter via Signal or WhatsApp at +1 (650) 636-6268 using a non-work phone, email at rprice@jkmperu.com, WeChat at robaeprice, or Twitter DM at @robaeprice. (PR pitches by email only, please.) You can also contact Business Insider securely via SecureDrop.

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Reporter Rob Price sitting at a table
Rob Price
Rob Price was a senior correspondent at Business Insider, based in San Francisco. He wrote investigations and long-form features about platforms, people, and power in Silicon Valley.His stories variously led to attorney general investigations, large-scale internal reviews at major tech companies, high-profile personnel departures, citation by state and federal lawmakers, and the closure of a well-funded startup. His 2022 story on the Bitfinex hack is being adapted into a feature film, and in 2024 he received an SPJ NorCal Excellence in Journalism award for his reporting on AI and relationships.Rob's scoops and exclusive stories were cited by The New York Times, Bloomberg, the BBC, Associated Press, Reuters, CNBC, Politico, The Guardian, Axios, and many other national and international publications. His writing has also been published in or syndicated by The Washington Post, The Independent, Vice, Slate, and elsewhere, and he appeared on CNN, the BBC, CBS, Reuters, ABC Australia, and other broadcast media to discuss technology, business, and culture.He worked for Business Insider from 2015 to 2025. Prior to joining the features team, Rob covered Facebook and Silicon Valley, and before that wrote about tech business, policy, and the gig economy in London. Between September and October 2019, he was acting executive editor for Business Insider's UK bureau. He also sat on the board of directors for the San Francisco Press Club, the leading non-profit media advocacy group in the Bay Area, and was a volunteer crew member at the Marine Mammal Center, the world's largest animal hospital for marine mammals. You can contact Rob Price via email at robaeprice@gmail.com, or +1 650-636-6268 (Signal / WhatsApp / Cell). Selected stories:— They spoke out against their employer. Then they were hit with trade secrets suits.— The rise of 'shadow stand-ins'— App, Lover, Muse: Inside a 47-year-old Minnesota man's three-year relationship with an AI chatbot— Deel Speed: The inside story of a $12 billion HR startup's breakneck growth— Private islands, flying cars, and psychedelic parties: Inside the wild post-Google lives of Larry Page and Sergey Brin— 'I want your Instagram account': First came the threatening texts, followed by the SWAT teams. Then someone wound up dead.— Inside Iconiq: How Mark Zuckerberg's banker built a secret Silicon Valley empire and made billions— Gaia was a wildly popular yoga brand. Now it's a publicly traded Netflix rival pushing conspiracy theories while employees fear the CEO is invading their dreams— A drunken late-night assault allegation has roiled the secretive world of Mark Zuckerberg's private family office. Personal aides are speaking out about claims that household staff endured sexual harassment and racism from their colleagues.
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