The acknowledgment was part of a broader disclosure by Facebook on Wednesday about the ways in which various levels of user data have been taken by everyone from malicious actors to ordinary app developers. Cambridge Analytica did work for the Trump campaign during the 2016 presidential election, but a spokesperson for the Trump campaign told ABC News in a statement that the campaign used the RNC for its voter data and not Cambridge Analytica.
In response to a question from Business Insider on a conference call asking if anyone had been fired over the revelation that a British data firm had taken user data from up to 87 million users or other data privacy issues, the Facebook CEO said that he has not fired anyone. "That was my mistake".
Among the changes Facebook says it is taking is to be more transparent about what apps people are interacting with, make it easier for users to see what information they have shared with those apps and make it easier for users to delete the apps if they wish.
In a second tweet, the company added, "Cambridge Analytica did not use GSR Facebook data or any derivatives of this data in the USA presidential election".
As a result, many people's public profile information had been "scraped" and matched to the contact details, which had been obtained from elsewhere.
Mr Zuckerberg will testify over the matter next week before the US House Energy and Commerce Committee, the panel said on Wednesday.
Tens of Thousands of Black Holes May Be at Milky Way's Center
And since most black holes can't even be spotted that way, they calculate that there are likely thousands of them there. There are good reasons the Milky Way's black holes tend to be in the center of the galaxy, Hailey said.
Facebook revealed on Wednesday that tens of millions more people might have been exposed in the Cambridge Analytica privacy scandal than previously thought. More than 70m USA users may have had their information passed on. He said it isn't enough for Facebook to believe app developers when they say they follow the rules.
"I don't think there's been a meaningful impact we've observed", Zuckerberg said. "We undertook our own internal review to determine the number of people potentially impacted".
Zuckerberg said Facebook came to the higher estimate by looking at the number of people who had downloaded a personality quiz app created by Cambridge University academic Aleksandr Kogan, or about 270,000 people, and then adding in the number of friends they had. Facebook said it has disabled the feature in its site's search function that enabled the data scraping, but the fact that so much user data may have been vulnerable was another setback to the company's efforts to restore confidence with users.
The scandal has kicked off investigations by Britain's Information Commissioner's Office, the U.S. Federal Trade Commission and by some 37 U.S. state attorneys general.
But in research sparked by revelations from a Cambridge Analytica whistleblower last month, Facebook determined that the problem of third-party collection of user data was far larger still and, with the company's massive user base, likely affected a large cross-section of people in the developed world.
Over half a million of the users whose personal data might have been compromised are from India.
But some of those companies, like Cambridge Analytica, may still have your data, for all that Facebook knows, and there's really no way to stop it being used to target you with ads.