"We have a problem in terms of privacy. And we have a problem in terms of propaganda," Sen. John Neely Kennedy, R-La., a member of the Judiciary Committee, said in an interview Monday. "And I'm hoping tomorrow that Mr. Zuckerberg doesn't spend a lot of time saying 'I'm sorry' and apologising, and accepting responsibility - we all know he's responsible."
Zuckerberg testifies first at a rare, joint hearing at 2:30 Tuesday afternoon (6.30 am Auckland time) before two Senate panels - the Commerce and Judiciary committees - meeting in joint session, with as many as 43 senators set to question the Facebook executive. The House Energy and Commerce Committee has its own hearing scheduled for Wednesday morning.
Zuckerberg, who had tried to avoid such a potentially fractious public encounter with lawmakers, already has made clear his desire to project contrition and a willingness to undertake changes, even endorsing legislation mandating a new level of transparency for political advertising online. But lawmakers from both parties are contemplating more aggressive legislative moves that could restrict which tech companies collect data and how they use it.
Democratic Sen. Edward J. Markey, Mass., for example, plans to introduce a bill Tuesday called the Consent Act that would require social giants like Facebook and other major web platforms to obtain explicit consent before they share or sell personal data.
"My sense is [Zuckerberg] takes it seriously because he knows there's going to be a hard look at regulation," Sen. Bill Nelson, Fla., the highest-ranking Democrat on the Commerce Committee, said after meeting with the Facebook executive privately on Monday.
Nelson added, "If it's not his site, then [something] else can be misused by people trying to do us harm. I believe he understands regulation can be right around the corner."
Lawmakers also have expressed interest in broadening their inquiry to other technology companies, including Google and Twitter. But this week's focus will be sharpest on Facebook.
The House committee released Zuckerberg's opening remarks on Monday, as he and top aides worked their way across Capitol Hill in a series of closed-door meetings with lawmakers.
"It's clear now that we didn't do enough to prevent these tools from being used for harm as well," Zuckerberg plans to testify, according to the transcript. "That goes for fake news, foreign interference in elections, and hate speech, as well as developers and data privacy. We didn't take a broad enough view of our responsibility, and that was a big mistake. It was my mistake, and I'm sorry. I started Facebook, I run it, and I'm responsible for what happens here."
The company has been reeling since the November 2016 election, during which phony news reports spread widely on its platform and Russian operatives mounted an ambitious campaign to divide American voters, damage Democrat Hillary Clinton and bolster the chances of Republican Donald Trump.
Facebook appeared to be recovering from those controversies until last month's revelation that Cambridge Analytica, a political consultancy hired by Trump and other Republicans, improperly gained access to data on 87 million Facebook users, including 71 million Americans. Last week, the company acknowledged a separate problem in which "malicious actors" were able to identify and collect data on Facebook users on such a massive scale that most of the company's 2.2 billion users were affected.
As the company has mobilised to quell rising political opposition, Facebook also has wrestled government investigations in the United States and Europe. The Federal Trade Commission is investigating violations of a 2011 consent decree over privacy policy at Facebook that could lead to record fines against the company.
