The revelations have sparked a global backlash against Facebook and has increased fears about how user data is shared.
Despite calls for Zuckerberg to step down, he told The Atlantic he will not.
Zuckerberg is also in Washington on Monday to have private meetings with lawmakers ahead of the public sessions. He is meeting with Senate Commerce Committee Ranking Member Bill Nelson, D-FL, a spokesman for Nelson confirmed to NBC News.
The company is under fire on other fronts. Zuckerberg has admitted Facebook did little to stop misuse of the platform by Russian-backed activists who planted messages of social division back in 2016.
Zuckerberg said in a blog post on Monday: “Looking back, it’s clear we were too slow identifying election interference in 2016, and we need to do better in future elections.”
In what is rapidly turning into Facebook’s worst scandal yet, Zuckerberg will also have to answer questions about what the company is doing to stop misuse of its platform in future elections in the U.S. and around the world. Facebook said Monday it would commission researchers to examine the effect of social media on “elections and democracy.”
The top lawyers for Facebook, Twitter and Google testified to the lawmakers back in November, but Zuckerberg and the key executives from Twitter and Google declined to attend.
“We called for Mark Zuckerberg to testify before all of this blew up,” Senator Amy Klobuchar, D-Minn., said on MSNBC’s “Kasie DC” on Sunday night. “This happened and now he’s coming.”
Klobuchar, a member of the Senate Judiciary Committee, told MSNBC’s Kasie Hunt, her big question for Zuckerberg is: “How do you fix this?”
Zuckerberg offered an answer in an interview with Vox last week: “We will dig through this hole, but it will take a few years.”
How to watch
The Senate Judiciary and Commerce Committees will stream the Tuesday session titled, “Facebook, Social Media Privacy, and the Use and Abuse of Data.” The session is scheduled to begin at 2:15 p.m. ET.
NBCNews.com will also livestream coverage of the event as well as host a liveblog to provide context and background on the proceedings.