Sen. Amy Klobuchar, D-Minn., raised the alleged harmful effects of Instagram, which is owned by Facebook, and the data whistleblower Frances Haugen leaked showing Facebook's own research found that more than 13% of teenage girls said that Instagram made their thoughts of suicide worse.

"What did they do? They proposed 'Instagram for Kids,' now been put on pause, because of public pressure," Klobuchar blasted, before asking Haugen if Facebook knows data has shown Instagram also promotes eating orders in young girls.

"Facebook knows that they are leading young users to anorexia content," Haugen said.

An internal Facebook study shown to lawmakers by Haugen that Klobuchar cited said 17% of teen girls said Instagram makes eating disorders worse.

Comparing the social media giant to tobacco companies targeting youth, Haugen said that Facebook is deliberately designing their product to be addictive.

"Facebook has a long history of having a successful and very effective growth division where they take little, tiny tweaks and constantly, constantly, constantly trying to optimize is to grow," she added.

Asked whether CEO Mark Zuckerberg would be the one to dictate the decisions around Facebook's algorithm, whistleblower Frances Haugen said yes, noting his "unique" role in the company, noting he holds over 55% of all voting shares.

"There are no similarly powerful companies that are as unilaterally controlled, and in the end, the buck stops with Mark," Haugen said. "There's no one currently holding Mark accountable but himself."

In her opening statement, Haugen echoed Sen. Richard Blumenthal, D-Conn., in comparing Facebook's reckoning to a "big tobacco moment" and called on the government to take action.

"As long as Facebook is operating in the shadows, hiding its research from public scrutiny, it is unaccountable. Until the incentives change. Facebook will not change," she said.

"When we realized big tobacco is hiding the harms that it caused, the government took action. When we figured out cars were safer than seatbelts, the government took action. And when our government learned that opioids are taking lives, the government took action," she said. "I implore you to do the same here today."

Haugen said that Facebook "wants you to believe that the problems we're talking about are unsolvable. They want you to believe in false choices. They want you to believe that you must choose between a Facebook full of divisive and extreme content or losing one of the most important values."

"I'm here today to tell you that that's not true," she said.

Frances Haugen, the former Facebook project manager turned whistleblower, appearing before the Senate pleaded with lawmakers to take action as the company makes "disastrous" internal choices that put profits before people.

"I used to work at Facebook. I joined Facebook because I think Facebook has the potential to bring out the best in us. But I'm here today because I believe Facebook's products harm children stoke division and weaken our democracy," she began. "The company's leadership knows how to make Facebook and Instagram safer, but won't make the necessary changes as they put their astronomical profits before people."

"Congressional action is needed. They won't solve this crisis without your help," she said.

While she said she believes in the potential of Facebook, the company must “do better.”

"Yesterday, we saw Facebook get taken off the internet. I don't know why it went down, but I know that for more than five hours, Facebook wasn't used to deepen divides destabilize democracies and make young girls and women feel bad about their bodies. It also means that millions of small businesses, weren't able to reach potential customers, and countless photos of new babies weren't joyously celebrated by family and friends around the world," she said.

Also introducing herself, Haugen said she’s worked as a product manager at big tech companies since 2006, including Google, Pinterest and Yelp with jobs focused on algorithmic products.

"I understand how complex and nuanced these problems are. However, the choices being made inside of Facebook are disastrous for our children or our public safety, or our privacy and for our democracy. And that is why we must demand Facebook make changes," she said.

Haugen said that the result of putting "profits before people" can evolve beyond "dangerous online talk" and has led to actual violence that harms and even kills people.

"The documents I have provided to Congress prove that Facebook has repeatedly misled the public about its own research reveals about the safety of children, the efficacy of its artificial intelligence systems and its role in spreading divisive and extreme messages," she said.

In a rare show of bipartisanship in a divided Washington, GOP Sen. Marsha Blackburn, the subcommittee's ranking member, echoed Sen. Richard Blumenthal, D-Conn., in bashing Facebook for "turning a blind eye" to harm it's allegedly causing its users, particularly young girls.

Blackburn accused Facebook of trying to minimize the information contained in the documents Haugen turned over, responding to Facebook accusations that Haugen is misrepresenting its data.

"Having seen the data that you've presented and the other studies that Facebook did not publicly share, I feel pretty confident that it is Facebook who has done the misrepresenting," Blackburn said.

"Here is what else we know -- Facebook is not interested in making significant changes to improve kids' safety on their platforms, at least not when that would result in losing eyeballs on posts or decreasing their ad revenues," she continued, saying the platform is threatened by new platforms like Tik Tok.

Blackburn thanked Blumenthal’s team, along with Haugen, as the committee examine whether Facebook is in violation of or evading the Children's Online Privacy Protection Act, among exploring other potential regulations. Facebook denies the allegations.

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.