Every congressional hearing with the tech CEOs has been rife with promises they will "get back" to lawmakers on questions they either can't or don't want to answer.
Here are a few of the questions Jack Dorsey, Mark Zuckerberg and Sundar Pichai pledged to follow up on privately.
"Facebook is proactively working with law enforcement to disrupt real-world violent attempts that stem from some of that activity that originated on your platform. Can you tell me specifically how many threats have you proactively referred to local or state law enforcement?"
Democratic Sen. Gary Peters, the top Democrat on the House Homeland Security Committee, spent his seven minutes politely questioning Zuckerberg about the spread of violent extremism on Facebook and how it can lead to real-world harm. He cited the recent attempted kidnapping of Michigan Gov. Gretchen Whitmer, which was in part organized on Facebook.
Facebook has said it started proactively communicating with law enforcement about the militia group behind the kidnapping plot at least six months ago and it was removed from the platform on June 30.
Zuckerberg said he doesn't "know the number" of proactive referrals it has made to law enforcement about alarming extremist activity but pledged to "follow up with you on that."
"It is increasingly common that our systems are able to detect when there's potential issues," Zuckerberg said.
"Have you seen a reduction in your platform's facilitation of extremist group recruitment?"
An internal Facebook study in 2016 found that 64% of people joining extremist groups on Facebook were due to its own recommendation tools, according to a recent Wall Street Journal report. Since then, Facebook has changed some of its policies and approaches to extremism and online radicalization.
When Peters asked if Facebook has seen a reduction in that activity since it has changed its policies over the past four years, Zuckerberg said he wasn't "familiar" with the study but would get the senator "more information on the scope of those activities."
"How much are your companies currently spending defending lawsuits related to user content?"
None of the CEOs was able to answer this. "I can get back to you," Zuckerberg said.
"We spend a lot on legal lawsuits but not sure what of it applies to content-related issues, but happy to follow up," Pichai said. Dorsey said he didn't "have those numbers."
Republican Sen. Jerry Moran said he wanted to use their answers to "highlight" a tension in the conversation: It could be extremely costly for businesses smaller than Google, Twitter and Facebook to afford the amount of lawsuits that most Section 230 reforms would enable.
"Whatever the numbers are, you indicate they're significant — an enormous amount of money and employee time, contract labor time in dealing with modification of content," Moran said. "These efforts are expensive, and I'd highlight for my colleagues the committee that they wouldn't be any less expensive — perhaps less in scale but not less in cost — for startups and small businesses."
"Gotcha" questions about anti-conservative bias
Each of the CEOs diligently pledged they would "follow up" with various GOP senators over questions related to conservative bias. Dorsey said he would get back to Senate Commerce Committee Chairman Roger Wicker about how long it took to take down a particular tweet from a Chinese communist party leader. Zuckerberg pledged to follow up with Sen. John Thune with a list of articles that Facebook has "suppressed" and to discuss a "former Biden staffer" who deals with election-related content at Facebook.
Each of the CEOs spent some time debunking allegations that they routinely censor right-wing voices, but they punted on the vast majority of opportunities to hammer home that message.