Facebook whistleblower Frances Haugen appeared Tuesday before the Senate Commerce Committee, where she told a story of negligence by her former employer that she says endangers the mental health of children and even national security. 

Haugen, who revealed herself as the leaker behind the Wall Street Journal’s article series “The Facebook Files," previewed her testimony with an appearance on CBS News’ "60 Minutes." In her interview, Haugen detailed how Facebook routinely put profits over public safety. 

Facebook has fervently denied Haugen's claims, touting their past work on countering misinformation and accusing reporters of selectively writing about facts that are damaging to its reputation. 

Haugen’s testimony touched on each of these claims and potentially provided new ways to safeguard social media. Here are five of the biggest takeaways from her hearing today. 

Haugen Said Facebook Can 'Destroy' Her For Breaking Her Silence

In her opening statement, Haugen explained her motivations for speaking out against one of the most profitable companies in the world and acknowledged the possible professional risks she faced in retaliation. 

“I believe what I did was right and necessary for the common good, but I know Facebook has infinite resources, which it could use to destroy me,” said Haugen. 

Facebook has been subject to withering criticism from lawmakers and activists for its perceived failure to adequately address abuse on the platform.

The New York Times reported that Facebook is shifting to a more aggressive posture in protecting its brand as well as create distance for CEO Mark Zuckerberg from any scandals. It has even reportedly so far as to use its own News Feed to prioritize positive stories about the company in a bid to fight back against negative stories. 

During Haugen’s remarks, members of Facebook’s communication team took to Twitter to refute points in her testimony. Andy Stone, a Facebook communications executive, said that Haugen had “no direct knowledge” of child safety or Instagram issues, something Haugen admitted herself in the hearing. 

Sen. Marsha Blackburn, R-Tenn., acknowledged Stone’s tweets in the hearing and extended an "invitation to step forward" to discuss Facebook's "targeting of children" under oath.

Haugen Said Facebook 'Knows It Is Leading Young Users' To Content That Promotes Eating Disorders

Under questioning from Sen. Amy Klobuchar, D-Minn., Haugen was asked if Facebook consciously used its algorithm to push "outrageous content" promoting eating disorders to young girls. 

The whistleblower responded in the affirmative before describing how Facebook’s algorithm used what she called a “proactive incident response” that can lead young users suffering from eating disorders to related content like anorexia. 

"Facebook knows engagement-based ranking, the way they pick the content in Instagram for young users, for all users,” said Haugen. 

Facebook’s own research showed that Instagram was capable of negatively impacting the mental health of teenagers, especially girls. According to an internal Facebook study, up to 32% of teenage girls struggling with body image issues said that Instagram use made them feel worse. 

In public testimony from March, CEO Mark Zuckerberg downplayed the negative impact of Instagram on young people’s mental health.

Last week, Antigone Davis, Facebook’s head of global safety, made similar comments before Congress by saying that the leaked research was "not a bombshell." 

Haugen Said That Mark Zuckerberg Is Accountable For Missteps

Senators took the time to single out Facebook’s founder and CEO for his failure to address missteps and abuses on his platform. Haugen said her former boss does share responsibility for these failures, especially given his powerful stature. 

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

While Haugen stopped short of accusing Zuckerburg or other top executives of intentionally creating the problems at the center of the controversy, she blamed the “metrics driven” culture they fostered for exacerbating them.

Haugen added that Facebook was an essentially “flat” organization when it came to decision-making, but as the head of the company Zuckerberg bore responsibility in the end.

As Haugen testified, Zuckerberg is a uniquely powerful executive within the industry. He currently holds over 50% of voting shares in Facebook, providing him the strongest single say over its decisions. 

At the end of the hearing, Facebook released a statement that said Haugen "never attended a decision-point meeting with C-level executives" and that it did not agree with her "characterization of the many issues she testified about."

Haugen Raises National Security Concerns About Facebook’s Actions

Facebook’s platform, like other social networks, has been criticized for allowing authoritarian states to abuse them and for terrorists making use of it for planning or recruitment. 

Haugen, who last worked as a product manager on Facebook’s counterespionage efforts, said that these actions are taking place on Facebook and that it is "very aware" of them.

She recounted her most recent experience as working as a project manager on Facebook's counterespionage team. There she was able to witness China's use of Facebook to spy on members of the Uyghur minority around the world and espionage conducted over Facebook by Iran against other states.

To be certain, Facebook has published public reports about its efforts to take down foreign information operations, counterterrorism efforts and counterespionage work since the aftermath of the 2016 Russian interference in the U.S. presidential election. 

Following the hearing, Facebook's head of security policy, Nathaniel Gleicher, took to Twitter to defend the work of his team and share examples of their work over the years, including on thwarting Chinese actors.

Gleicher said that Facebook considers security work a “high priority” and said that the actions it announced in the past were among its “most public efforts” to “protect people on our platform.” 

However, Haugen told Congress that security work suffered from “consistent understaffing” that gives her cause for concern. She said on "60 Minutes" that key parts of the security team were dismantled and repositioned throughout Facebook which hurt their ability to do more in advance about the Jan. 6 Capitol riot.  

Facebook's Vice President of Global Affairs Nick Clegg dismissed accusations that it was responsible for the Capitol riot as "ludicrous."

Facebook Needs New Regulations, But Does Not Need To Be Broken Up

In her initial remarks, Haugen stated that she believes Facebook needs stronger regulations that go beyond tweaks to existing laws. 

Part of her motivation for blowing a whistle on Facebook was because she felt the company is not forthcoming about everything it knows with Congress, regulators or the public. She said the "core of the issue is that no one can understand Facebook's destructive choices" than the company itself, and that more transparency from it was required to make effective new regulations. 

Comparing Facebook's openness to that of Big Tobacco in the 1990s, Haugen said only independent researchers and regulators with full access to Facebook's data would make effective regulations possible.

Going further, she added that Facebook should not be left responsible to police itself because "they have repeatedly proved that they do not deserve our blind faith."

One solution that Haugen disagreed with were calls to break up Facebook that have been echoed by some lawmakers, including Rep. Alexandria Ocasio-Cortez, D-N.Y. 

Haugen expressed her view that the problem lay more in the design of the algorithms than the size of the company. Even if Facebook was broken up, she said that "these systems are going to continue to exist and be dangerous even if broken up."

Facebook has agreed that new regulations may be needed in the social media age and put the onus on Congress to enact them.

Klobuchar, however, said that Facebook itself was preventing any new regulations through “throwing a bunch of money” at well-heeled lobbyists to dissuade lawmakers from doing more.