NEW YORK — Get ready to find out if your Facebook data has been swept up in the Cambridge Analytica scandal.
Starting Monday, the 87 million users who might have had their data shared with Cambridge Analytica will get a detailed message on their news feeds. Facebook says most of the affected users (more than 70 million) are in the U.S., though there are over a million each in the Philippines, Indonesia and the U.K.
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In addition, all 2.2 billion Facebook users will receive a notice titled "Protecting Your Information" with a link to see what apps they use and what information they have shared with those apps. If they want, they can shut off apps individually or turn off third-party access to their apps completely.
NBC's Savannah Guthrie floated the idea of notifying users in an interview with Sheryl Sandberg last week. Sandberg initially pushed back on the notion, saying that Facebook was wary of sending too many notifications to its users.
"People are worried about apps like Cambridge Analytica," Sandberg said. "So we're not just notifying on Cambridge Analytica."
Facebook previously released a feature that made it easier to see which apps users had connected to their accounts.
Reeling from its worst privacy crisis in history — allegations that this Trump-affiliated data mining firm may have used ill-gotten user data to try to influence elections — Facebook is in full damage-control mode. CEO Mark Zuckerberg acknowledged that he made a "huge mistake" in failing to take a broad enough view of what Facebook's responsibility is in the world.
Zuckerberg is set to testify before the Senate Judiciary and Commerce Committees as well and the House Energy and Commerce Committee on April 10 and 11 respectively, the committees announced last week.
He is also meeting privately with lawmakers on Monday, according to Reuters, which cited anonymous sources.
A spokesman for Senate Commerce Committee ranking member Bill Nelson, D-Fla., told NBC News that Zuckerberg will meet with Nelson on Monday afternoon ahead of Zuckerberg’s appearance before Tuesday's joint hearing of the Senate Judiciary and Commerce Committee.
NBC News was not immediately able to confirm which other lawmakers Zuckerberg planned to meet with on Monday ahead of the hearings.
In recent days, the Facebook scandal has only gotten worse: Cambridge Analytica whistleblower Christopher Wylie previously estimated that more than 50 million people were compromised by a personality quiz that collected data from users and their friends. But in an interview aired Sunday on NBC's "Meet the Press," Wylie said the true number could be even larger than 87 million.
That Facebook app, called "This is Your Digital Life," was a personality quiz created in 2014 by an academic researcher named Aleksander Kogan, who paid about 270,000 people to take it. The app vacuumed up not just the data of the people who took it, but also — thanks to Facebook's loose restrictions — data from their friends, too, including details that they hadn't intended to share publicly.
Facebook later limited the data apps can access, but it was too late in this case.
Zuckerberg said Facebook came up with the 87 million figure by calculating the maximum number of friends that users could have had while Kogan's app was collecting data. The company doesn't have logs going back that far, he said, so it can't know exactly how many people may have been affected.
Cambridge Analytica said in a statement Wednesday that it had data for only 30 million Facebook users.