Sen. Richard Blumenthal, D-Conn., the subcommittee’s chair, said at the opening of Tuesday's hearing that Facebook is facing its "Big Tobacco moment -- a moment of reckoning," and that it's time to hold big tech accountable.

"Facebook knows its products can be addictive and toxic to children. And it's not just that they made money, again, it's that they value their profit more than the pain that they cause the children and their families," Blumenthal said, while whistleblower Frances Haugen nodded along.

“Facebook exploited teens using powerful how algorithms and amplified their insecurities,” Blumenthal said, adding he hopes Haugen can address the question as to whether there is such a thing as a safe algorithm for the social media giant.

Blumenthal, whom Haugen has allegedly showed leaked Facebook documents to, said the company’s “profit was more important than the pain that they caused" and called on CEO Mark Zuckerberg to come before the committee.

“Mark Zuckerberg ought to be looking at himself in the mirror today, and yet, rather than taking responsibility and showing leadership, Mr. Zuckerberg is going sailing," Blumenthal said, in an apparent reference to the billionaire's recent social media posts.

"Facebook appears to have misled the public and investors, and if that's correct, it out to face real penalties as a result of that and misleading and deceptive representation," he said.

Facebook CEO Mark Zuckerberg has still not publicly commented on whistleblower France Haugen’s claims that the company manipulated its algorithm to incentivize disinformation, hatred and polarization among its users.

Zuckerberg did, however, weigh in on Monday evening following the platform’s six-hour outage, apologizing for the disruption.

Nick Clegg, Facebook's vice president of global affairs, has responded to Haugen's claims on behalf of the company while Zuckerberg stays silent and said in a CNN interview on Sunday those making accusations that the company is commissioning research to "deliberately" brush it aside have it "back to front."

"If we didn't want to address those questions, we wouldn't commission the research in the first place," Clegg said.

Also among Haugen’s accusations is that Facebook relaxed safeguards surrounding the 2020 election content after Nov. 3, allowing misinformation to spread and fuel the Jan. 6 attack on the Capitol.

Clegg told CNN that blame "lies squarely with the people who inflicted the violence and those who encouraged them, including President Trump."

Sen. Richard Blumenthal, D-Conn., who chairs the Senate Commerce Subcommittee on Consumer Protection, Product Safety and Data Security, promised "riveting" testimony that would prove to be a "breakthrough moment" ahead of Tuesday's hearing.

"This whistleblower is one gutsy, smart, strong woman who is speaking truth to the nation about how Facebook is dragging children into dark places and deepening their insecurities with online bullying, self-injuries, suicide, eating disorders, and I think she will tell us what it's like to see the top Facebook executives make decisions that profit Facebook at the expense of children's safety, how they put children’s safety above -- below profit-making motive," Blumenthal told reporters Monday evening.

Blumenthal said the documents Haugen has provided show a "searing indictment of the top corporate management of Facebook ignoring their own study, their own surveys and research that showed how they were putting kids in danger, just so they could profit more."

He also alleged Facebook has been "utterly unresponsive" to the committee's requests to disclose their own studies and said he hopes Haugen coming forward will encourage other whistleblowers.

Frances Haugen, a former Facebook data scientist turned whistleblower, is scheduled to testify before the Senate Consumer Protection Subcommittee at 10 a.m. on Facebook and Instagram’s impacts on young users in a hearing entitled, "Protecting Kids Online: Testimony from a Facebook Whistleblower. "

Beyond alleging Facebook’s knowledge of its platforms’ negative impact on teenagers and young girls, Haugen has reportedly come forward with documents showing the social media giant has also ignored but is aware of how hate speech and misinformation are emphasized on their sites.

Haugen, who revealed her identity during a Sunday interview on CBS' "60 Minutes" has been cooperating with the offices of Sen. Richard Blumenthal, D-Conn., and Sen. Marsha Blackburn, R-Tenn., chair and ranking member of the Senate committee that is assessing potential regulations for the social media giant.

After more than three hours of testimony, the Senate Commerce subcommittee hearing with Facebook whistleblower Frances Haugen, who has accused the company of deceiving users and investors and putting "profits before people," has adjourned.

While lawmakers battle it out over President Joe Biden’s agenda, they united on Tuesday to blast Facebook CEO Mark Zuckerburg’s silence on Haugen accusations, which raise alarms about the mental health of children and real-world dangers of hate speech she said Facebook knows it perpetuates but ignores. Lawmakers said she has provided hundreds of pages of documents of internal data to back her claims.

Sen. Richard Blumenthal, D-Conn., the subcommittee chair, closed by reading a text he said he received from a constituent who said he was in tears watching the hearing because, he said, he's seen first-hand how Instagram has changed his teenage daughter.

"'My 15-year-old daughter loved her body at 14. Was on Instagram constantly and maybe posting too much. Suddenly she started hating her body. Her body dysmorphia, now anorexia, and was in deep deep trouble before we found treatment. I fear she'll never be the same,'" Blumenthal said, quoting the father.

Haugen said "because of the nature of engagement-based ranking and amplification of interests," Facebook and Instagram users are "pushed towards extreme dieting and pro-anorexia content very rapidly" -- but that the algorithm perpetuating that could be changed.

After raising new allegations concerning Zuckerberg’s actions, national security concerns, and employee bonuses tied to a system shown to fuel misinformation, Haugen closed with a call to Congress to address Facebook’s growth and provide oversight as it’s historically done for other industries, like tobacco, in the past.

Saying that modern technological systems "walled off," Haugen also called on more whistleblowers with direct knowledge of wrongdoings in big tech to step forward.

"The fact we're being asked these false choices -- it's just an illustration of what happens when the real solutions are hidden inside of companies," she said. "We need more tech employees to come forward through legitimate channels, like the SEC (Securities and Exchange Commission) or Congress, to make sure that the public has the information they need in order to have technologies be human-centric, not computer central."