Facebook said on Wednesday personal data on as many as 87 million users was improperly shared with British political consultancy Cambridge Analytica.
The new figure eclipses a previous estimate of 50 million in a further embarrassment to the social network roiled by a privacy scandal.
The announcement came as Facebook unveiled clearer terms of service to enable users to better understand data sharing, and as a congressional panel said chief executive Mark Zuckerberg would appear next week to address privacy issues.
Facebook’s chief technology officer Mike Schroepfer released the new figures on affected users as he discussed implementation of new privacy tools for users of the huge social network.
“In total, we believe the Facebook information of up to 87 million people — mostly in the US — may have been improperly shared with Cambridge Analytica,” he said.
The new estimate could deepen the crisis for Facebook, which has been pressured by the disclosures on hijacking of private data by the consulting group working for Donald Trump’s 2016 campaign.
Schroepfer said new privacy tools, which had been announced last month, would be in place by next Monday.
“People will also be able to remove apps that they no longer want. As part of this process we will also tell people if their information may have been improperly shared with Cambridge Analytica,” he said.
“Overall, we believe these changes will better protect people’s information while still enabling developers to create useful experiences.”