Sen. Marsha Blackburn, R-Tenn., ranking member of the Senate subcommittee hearing testimony from the Facebook whistleblower on Tuesday, responded directly to a Facebook spokesperson after a compelling first round of testimony from Frances Haugen.

Andy Stone had tweeted earlier and pointed out that Haugen did not work on child safety or Instagram research issues. Haugen, who worked as a project data manager was assigned to Facebook's civic integrity group.

Blackburn blasted Stone to come before Congress himself.

"I will simply say this to Mr. Stone: If Facebook wants to discuss their targeting of children -- if they want to discuss their practices, privacy invasion or violations of the Children Online Privacy Act, I am extending to you an invitation to step forward, be sworn in and testify before this committee. We would be pleased to hear from you and welcome your testimony," she said.

Whistleblower Frances Haugen reiterated to the Senate panel that Facebook's own data raises the concerns she's presenting to them and that the platform has unprecedented access into people's lives worldwide.

"They shouldn't be allowed to keep secrets when people's lives are on the line," she said. "To be clear, if they make $40 billion a year, they have the resources to solve these problems. They're choosing not to solve them."

She also told lawmakers she thinks there should be greater consideration to age when it comes to using any social media after her 15 years in big tech, keeping the focus of her message on its harmful effects on kids.

"I strongly encourage raising age limits to 16 or 18 years old, based on looking at the data around, problematic use or addiction on the platform and Children's self-regulation issues," she said. 

She shared particular concern with Instagram, saying internal research shows the platform is "distinctly worse" than other social media platforms because, she said, "it’s about bodies and about comparing lifestyles."

After whistleblower Frances Haugen raised concerns around Facebook's resourcing of counterterrorism and teams intended to counter foreign influence, lawmakers opened the door to holding another hearing. 

"I believe Facebook's consistent understaffing of the counterespionage, information operations and counterterrorism teams is a national security issue, and I'm speaking to other parts of Congress about that," Haugen said.

Sen. Dan, Sullivan, R-Alaska, followed up, "So you're saying in essence that the platform, whether Facebook knows it or not, is being utilized by some of our adversaries in a way that helps push and promote their interests at the expense of America's?"

"Yes," she replied. "Facebook is very aware that this is happening on the platform, and I believe the fact that Congress doesn't get a report of exactly how many people are working on these things internally is unacceptable because you have a right to keep the American people safe."

“I have strong national security concerns about how Facebook operates today,” she added.

Sen. Richard Blumenthal, D-Conn., then raised the possibility of holding a second hearing with Haugen on the issue and went on to thank her for her bravery and called for other whistleblowers to come forward.

Facebook said communications staffer Andy Stone would live-tweet through the Senate hearing to respond to Frances Haugen's testimony.

"Just pointing out the fact that @FrancesHaugen did not work on child safety or Instagram or research these issues and has no direct knowledge of the topic from her work at Facebook," he tweeted. "As she herself just said under oath, 'I don't work on it.'"

Sen. Amy Klobuchar, D-Minn., had asked if teenagers are some of Facebook's most profitable users.

"I'm sure they are some of the more profitable users on Facebook, but I do not work directly on them," Haugen said.

Facebook also pointed to a May op-ed in CNBC from Nick Clegg, Facebook vice president of global affairs, calling for "bipartisan approach on internet regulation."

But lawmakers from both parties on Tuesday, in a normally divided Washington, were united in blasting the social media giant after they said internal documents Haugen presented to them showed Facebook ignored its own evidence that it harms young users and fuels hate speech. Haugen also alleged CEO Mark Zuckerberg had the opportunity to intervene but dismissed the concern.