Facebook may have hit a red line this time

Facebook's previous major scandals barely dented its global dominance, but experts said the tech giant may have hit a red line this time: evidence that it knew children using its apps were at risk of being harmed.

A day after damning testimony to US lawmakers from Facebook whistleblower Frances Haugen, the long-established barriers to regulation -- stalled legislation, free speech protections and tech's rapid advances -- were still in place.

But an insider with the company's own documents, showing that Facebook knew its tools risked worsening young people's eating disorders or suicidal thoughts, may have been a turning point.

"The topic of kids being affected negatively by using Instagram or other social media apps is something Republicans and Democrats can agree upon," said Paul Barrett, deputy director of New York University's Stern Center for Business and Human Rights.

He said the level of cross-party civility in Tuesday's hearing was something he'd not seen in years, showing some of the impact of the drubbing Facebook has taken because of Haugen's leaks.

She exposed reams of internal research to authorities and The Wall Street Journal in an exposure that has fueled one of the social network's most serious crises yet.

The company has bounced back from other scandals like the one involving Cambridge Analytica, a British consulting firm that used the personal data of millions of Facebook users to target political ads.

In that case, Facebook's CEO Mark Zuckerberg went to Washington to apologize and the company agreed to a $5 billion settlement with US regulators.

American lawmakers have not passed any laws targeting the company, despite the outrage over the hijacking of personal data of millions of users ahead of the 2016 US presidential election.

However, this new revelation about Facebook's behavior has seemingly hit a raw nerve.

"There are certain political issues that tend to be galvanizing for folks and child protection is a key one," said Allie Funk, senior research analyst in technology and democracy at Freedom House, a US think tank.

It's clear also that Facebook would not submit without a fight, if lawmakers in the hyper-polarized US Congress manage to move forward with any of the several already existing proposals.

Zuckerberg said in a post on his account that Haugen's assertion that his company prioritizes profit over safety was "just not true."

For her part, Nora Benavidez, a Facebook accountability expert, said she saw in the hearing a catalyzing moment that was broader than the impact on children.

"I think it's now more that there are tens of thousands of pages of documents... that clearly Congress has access to," she said. "The phrase is 'Too big to ignore.'"