Facebook now says up to 87 million users' data improperly shared

The Facebook update comes as CEO Mark Zuckerberg agrees to testify to Congress.

In a rare call with reporters Wednesday afternoon, Zuckerberg was contrite. "It’s clear now that we didn't do enough at preventing abuse," he said, adding, "We didn't take a broad enough view of what our responsibilities were. That was a huge mistake. It was my mistake."

Zuckerberg conceded he was "too flippant" in referring to potential problems in the 2016 election year as "crazy" and when asked why Facebook wasn't doing audits all along he said, "Knowing what I know today, we should've done more and we will."

"I wish that I could snap my fingers and in three months or six months have solved these issues," he said, adding he thinks fixing privacy concerns will be "a multi-year effort."

The House Energy and Commerce Committee announced earlier Wednesday that Zuckerberg will testify in person on April 11. Late Wednesday, the Senate Judiciary and Commerce committees announced a joint hearing with Zuckerberg next Tuesday, April 10.

“Using the RNC data was one of the best choices the campaign made. Any claims that voter data were used from another source to support the victory in 2016 are false,” the statement said.

Cambridge Analytica did not respond to ABC News’ attempts Wednesday to get comment on Zuckerberg agreeing to appear before the committee, but did issue a new statement responding to Facebook’s user data announcement. In its statement, Cambridge Analytica pushed back on the new figure of 87 million and shifted blame to a third party research firm.

“Cambridge Analytica licensed data for no more than 30 million people from GSR, as is clearly stated in our contract with the research company. We did not receive more data than this,” the statement said, adding, “Our contract with GSR stated that all data must be obtained legally, and this contract is now a matter of public record. We took legal action against GSR when we found out they had breached this contract.”

"GSR" refers to Global Science Research, the firm founded by Aleksandr Kogan, the Cambridge University researcher who collected information on millions of Americans through Facebook for Cambridge Analytica.

“We did not use any GSR data in the work we did in the 2016 US presidential election,” the statement added.

Trump administration sanctions Russians for 2016 election interference, other cyber attacks

“This hearing will be an important opportunity to shed light on critical consumer data privacy issues and help all Americans better understand what happens to their personal information online,” said committee chairman Rep. Greg Walden, R-Ore., and ranking member Rep. Frank Pallone Jr., D-N..J., in a joint statement announcing Zuckerberg’s appearance.

“We appreciate Mr. Zuckerberg’s willingness to testify before the committee, and we look forward to him answering our questions on April 11th,” Walden and Palone wrote.

Senate panel sets April 10 for Facebook CEO to testify

Last month, Facebook sent a handful of senior staff to brief aides to a number of key Senate and House committees on privacy concerns.

Top Stories

Top Stories

Top Stories

Top Stories

ABC News Live

ABC News Live

24/7 coverage of breaking news and live events