Here’s what you need to know in advance of the hearings.
What time are the hearings:
Zuckerberg will testify before the Senate Judiciary and Commerce committees at 2:15 p.m. ET Tuesday.
He will be before the House Energy and Commerce Committee at 10 a.m. ET Wednesday.
How can I watch:
Click here to watch Mark Zuckerberg's joint hearing before the Senate Judiciary and Commerce committees on Tuesday.
Go to YouTube or C-SPAN on Wednesday to watch Zuckerberg's hearing before the House Energy and Commerce Committee.
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Why is he being called:
Zuckerberg was invited to testify before Congress after Facebook officials initially admitted last week that 50 million of its users had information “improperly shared” when a British psychologist “scraped” data from people who took an online “quiz” and provided personal information to a firm that used the information to profile potential voters.
A few days later, that number was amended as the company's chief technical officer, Mike Schroepfer, said that instead of 50 million people having their information improperly shared with the political research firm Cambridge Analytica, "In total, we believe the Facebook information of up to 87 million people — mostly in the U.S. — may have been improperly shared" with the company.
In addition to addressing concerns over the sharing of information, the company has faced questions about political ads and posts on the site prior to the 2016 presidential election.
Zuckerberg told reporters last week that he made a "huge mistake" in failing to make clear what Facebook's responsibility is to its users.
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Who will be questioning him:
On Tuesday, Zuckerberg will be testifying at a joint hearing of the U.S. Senate Judiciary and Commerce committees. The members of those committees are:
Chuck Grassley, Iowa, (chairman)
Orrin Hatch, Utah
Lindsey Graham, South Carolina
John Cornyn, Texas
Mike Lee, Utah
Ted Cruz, Texas
Ben Sasse, Nebraska
Jeff Flake, Arizona
Mike Crapo, Idaho
Thom Tillis, North Carolina
John Neely Kennedy, Louisiana
Dianne Feinstein, California, (ranking member)
Patrick Leahy, Vermont
Dick Durbin, Illinois
Sheldon Whitehouse, Rhode Island
Amy Klobuchar, Minnesota
Chris Coons, Delaware
Richard Blumenthal, Connecticut
Mazie Hirono, Hawaii
Kamala Harris, California
Cory Booker, New Jersey
John Thune, South Dakota, (chairman)
Roger Wicker, Mississippi
Roy Blunt, Missouri
Ted Cruz, Texas
Deb Fischer, Nebraska
Jerry Moran, Kansas
Dan Sullivan, Alaska
Dean Heller, Nevada
Jim Inhofe, Oklahoma
Mike Lee, Utah
Ron Johnson, Wisconsin
Shelley Moore Capito, West Virginia
Cory Gardner, Colorado
Todd Young, Indiana
Bill Nelson, Florida, (ranking member)
Maria Cantwell, Washington
Amy Klobuchar, Minnesota
Richard Blumenthal, Connecticut
Brian Schatz, Hawaii
Ed Markey, Massachusetts
Tom Udall, New Mexico
Gary Peters, Michigan
Tammy Baldwin, Wisconsin
Tammy Duckworth, Illinois
Maggie Hassan, New Hampshire
Catherine Cortez Masto, Nevada
Jon Tester, Montana
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On Wednesday, Zuckerberg will answer questions before the U.S. House Energy and Commerce Committee. The members of that committees are:
U.S. House Energy and Commerce Committee
Greg Walden, Oregon (chairman)
Joe Barton, Texas
Fred Upton, Michigan
John Shimkus, Illinois
Tim Murphy, Pennsylvania
Michael C. Burgess, Texas
Marsha Blackburn, Tennessee
Steve Scalise, Louisiana
Bob Latta, Ohio
Cathy McMorris Rodgers, Washington
Gregg Harper, Mississippi
Leonard Lance, New Jersey
Brett Guthrie, Kentucky
Pete Olson, Texas
David McKinley, West Virginia
Adam Kinzinger, Illinois
Morgan Griffith, Virginia
Gus Bilirakis, Florida
Bill Johnson, Ohio
Billy Long, Missouri
Larry Bucshon, Indiana
Bill Flores, Texas
Susan Brooks, Indiana
Markwayne Mullin, Oklahoma
Richard Hudson, North Carolina
Chris Collins, New York
Kevin Cramer, North Dakota
Tim Walberg, Michigan
Mimi Walters, California
Ryan Costello, Pennsylvania
Buddy Carter, Georgia
Frank Pallone, New Jersey, (ranking member)
Bobby Rush, Illinois
Anna Eshoo, California
Eliot Engel, New York
Gene Green, Texas
Diana DeGette, Colorado
Mike Doyle, Pennsylvania
Jan Schakowsky, Illinois
K. Butterfield, North Carolina
Doris Matsui, California
Kathy Castor, Florida
John Sarbanes, Maryland
Jerry McNerney, California
Peter Welch, Vermont
Ben Ray Luján, New Mexico
Paul Tonko, New York
Yvette Clarke, New York
Dave Loebsack, Iowa
Kurt Schrader, Oregon
Joseph P. Kennedy III, Massachusetts
Tony Cárdenas, California
Raul Ruiz, California
Scott Peters, California
Debbie Dingell, Michigan
What will they be talking about in the hearings:
According to the House Energy and Commerce Committee website, the hearing will “shed light on Facebook’s use and protection of user data, and will help all Americans better understand what happens to their personal information online.”
The joint hearing between the Judiciary and Commerce committees hearing is titled, “The joint hearing before the Senate Judiciary and Commerce committees is titled: “Facebook, Social Media Privacy, and the Use and Abuse of Data.”
Blumentha had a more dire description of the hearing. "I think we're at a moment of reckoning. It's really high noon for Facebook and the tech industry,” Blumenthal said.
Zuckerberg will be asked how the personal information of 87 million Facebook users was mishandled, and what steps the company plans to take to try to avoid having users data “scraped.”
Another topic sure to be addressed is what Facebook needs to do to identify the source of political ads and control the spread of misinformation. Facebook announced last week that it will require buyers of political ads to verify their identity and location, and those who are unable to do so will be prohibited from running political ads on the platform.
“These steps by themselves won’t stop all people trying to game the system,” Zuckerberg said in a statement posted on Facebook. “But they will make it a lot harder for anyone to do what the Russians did during the 2016 election and use fake accounts and pages to run ads.”
Thune said in a statement that “More than any one issue, I’m interested in Mark Zuckerberg’s vision for the responsibility Facebook plans to take for what happens on its platform, how it will protect users’ data, and how it intends to proactively stop harmful conduct instead of being forced to respond to it months or years later.”
Markey told The Washington Post that he is looking for any "recourse for victims" following the revelation of the Cambridge Analytica data scrape.
Sen. Kennedy said on CBS' "Face the Nation" Sunday that he might be in favor of Congress regulating Facebook.
"I don't want to hurt Facebook. I don't want to regulate them half to death. But we have a problem. Our promised digital utopia has minefields in it ... . But my biggest worry with all of this is that the privacy issue and what I call the propagandist issue are both too big for Facebook to fix, and that's the frightening part," Kennedy said.
Here are others looking into Facebook’s operations:
Here’s a list of agencies and governments looking into Facebooks practices after the Cambridge Analytica scandal.
The Federal Trade Commission will look into whether Facebook was out of compliance with a 2011 agreement over privacy issues.
Thirty-seven states and territories have signed a letter asking Facebook to explain how they monitored the data app developers collected.
The European Union, the United Kingdom, Italy, India, Indonesia and Australia have all opened investigations into Facebook's operating practices.
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What has Facebook promised to do already:
In advance of his testimony this week, Zuckerberg announced several new measures to help protect the privacy of the companies 2 billion users.
Included in the new measures are requirements that people reveal their identities and verify who they are if they want to purchase ads.
To get verified, Zuckerberg wrote, “advertisers will need to confirm their identity and location. Any advertiser who doesn't pass will be prohibited from running political or issue ads.”
He went on to say that Facebook will “require people who manage large pages to be verified as well. This will make it much harder for people to run pages using fake accounts, or to grow virally and spread misinformation or divisive content that way.”
He also pledged to increase security on the site by adding employees to watch for questionable practices. “So all in, we now have about 15,000 people working on security and content review, and we’ll have more than 20,000 by the end of this year,” Zuckerberg said in a post last week.
Click here to see everything the company has proposed to do since news of the Cambridge Analytica breach was reported.