Sen. Elizabeth Warren and Sen. Maria Cantwell call for probes of Facebook - The...

Warren alleges that even when top executives became aware of the issues with the metric, they did not disclose them to their investors or the SEC.

“Facebook is not above the law,” she wrote in the letter, shared exclusively with The Washington Post. “The company’s executives cannot mislead investors, the SEC, its advertising customers, and the public about a core metric of its business model with impunity if such actions violate federal wire fraud or securities laws.”

Warren’s letter comes closely on the heels of another senior Democrat’s similar request. Sen. Maria Cantwell (Wash.), chair of the Commerce Committee, on Wednesday called the Federal Trade Commission to look into whether the company deceived its advertising customers on these same metrics. She asked the agency to investigate whether the company might have misrepresented its processes for ensuring brand safety, citing documents revealed by Haugen suggesting the company misrepresented its efficacy at removing hate speech.

Taken together, the letters underscore the intensity of the continued fallout in Washington over Haugen’s allegations and emphasize a possible path, with lawmakers turning to federal enforcers. Both letters cite complaints that Whistleblower Aid, a law firm representing Haugen, submitted to the SEC and shared with Congress.

The renewed political pressure underscores how Haugen’s revelations are having wide-ranging political consequences for Meta, the parent company of Instagram and Facebook, both in the United States and abroad. Earlier this week, senators including Cantwell grilled Adam Mosseri, head of Instagram, about the potentially negative effects of the social network on children, which Haugen’s documents exposed. Last month, a bipartisan coalition of state attorneys general opened a probe into Instagram’s impact on children and teens. And Haugen has testified before the European Parliament and British Parliament about the inner workings of the company. Sen. Richard Blumenthal (D-Conn.) in an October hearing with Haugen called for the FTC and SEC to investigate her claims.

At Wednesday’s hearing, Cantwell pressed Mosseri on both the potential reach metric and hate speech, items cited in her letter.

“As an advertising business I believe it’s in our interest to be as accurate as possible,” Mosseri said. “I think whenever we make mistakes we know that undermines our credibility, and advertising businesses are based on trust.” Cantwell replied with a dig. “Right, and they’re also based on being truthful to your advertisers,” she said.

The letters take aim at the core of Facebook’s business. Facebook makes the bulk of its money through advertising, which accounted for 97 percent of its revenue in its most recent quarterly earnings. Cantwell said it was important for the FTC to investigate the potential misrepresentation given the significant share that the company holds in the digital advertising market.

Haugen’s SEC complaint alleges that Facebook has “consistently misrepresented” the true number of people who advertisers can reach. The complaint argues that Facebook has inflated its numbers by not disclosing metrics about users with duplicate accounts on its platforms, causing it to overcharge advertisers on a vast scale. The complaint is one of at least eight that Haugen’s lawyers have said they filed with the agency.

“What we have learned from our client Frances Haugen’s disclosures is that when Facebook consistently deceives its investors, Congress and the public with PR spin and misleading metrics," Haugen’s legal team said in a statement to The Post. "We’re grateful for Senator Warren and Cantwell’s leadership on these issues and hope to see more Congressional leadership join in calling for reform.”

The letters also cite analyses, dating back to 2017, showing Facebook estimated the “potential reach” of the network to be a larger number of 18-to-34-year-olds than existed in each of the 50 states, according to Census Bureau data.

Facebook has since changed the name of the metric, announcing in October it would instead refer to it as “estimated audience size.”

Haugen has said she filed her complaints with the SEC, strategically targeting the agency because it is able to take action against companies that lie to investors. The letters suggest that key Democrats not only support Haugen’s argument but see agencies as a possible way to create consequences for Facebook.The SEC declined to comment on the letter or the status of Haugen’s complaints.

Both the FTC and the Justice Department have a history of probing Facebook. The FTC has an antitrust complaint leveled against the company, and it previously fined the company $5 billion to settle allegations that it deceived users about their privacy controls. The Justice Department in October settled with the company over findings its hiring practices intentionally discriminated against U.S. workers in favor of foreign workers.