Mark Zuckerberg, middle, attends President Donald Trump’s inauguration ceremony in Washington on Jan. 20, 2025. The Meta chief executive had recently announced upcoming layoffs.

Following the explosive response to her tell-all memoir, an ex-Facebook director-turned-whistleblower testified before Congress on Wednesday alleging Facebook’s close relationship with China poses serious risks to U.S. national security, a charge parent company Meta denies.

In “Careless People,” published last month, Sarah Wynn-Williams, a lawyer, former diplomat and ex-director of global public policy, who worked at Facebook for seven years starting in 2011, describes misconduct and harassment at the hands of Meta executives, including accusations that the company has lied about its relationship to China.

In her book, Wynn-Williams alleges sexual harassment at the hands of top executives. Meta has previously said her statements are “misleading” and “unfound.” She was fired in 2017, according to reports, for “poor performance.” In the book, she also accuses Meta CEO Mark Zuckerberg of lying during a 2018 Senate hearing and downplaying his relationship with the Chinese government.

Within a week of its publication, the book made it to the New York Times’ bestseller list not long before Meta hit Wynn-Williams with a gag order banning her from promoting the memoir, alleging it violated a nondisparagement contract she had signed. Attorneys representing the former executive said Meta is threatening her with a $50,000 fine each time she makes disparaging comments about the company.

Despite this, the former executive still agreed to testify before the U.S. Senate Judiciary Subcommittee on Crime and Counterterrorism on Wednesday afternoon. She has requested an investigation into the company’s potentially illegal activities.

“Sarah Wynn-Williams is facing down the barrel of a gun,” said U.S. Senate Pro Tempore and committee Chair Charles Grassley, a Republican from Iowa, ahead of her testimony.

In her opening remarks, which were made public ahead of the hearing, Wynn-Williams said she worked closely with Zuckerberg and, during her tenure, had a first-row glimpse into the company’s relationship with the Chinese Communist Party. During that time, she said, she witnessed Meta work “hand in glove” with Chinese officials.

Part of that relationship, she testified, included a “secret mission” to get Facebook into China. In 2015, she said, Meta and its executives began briefing China on critical emerging technologies, including AI, with the goal to “help China outcompete American companies.” She also said, during her tenure, the company was creating censorship tools and deleted the account of a Chinese dissident living in America at the request of Beijing, before allegedly lying about it to Congress.

“We are engaged in a high-stakes AI arms race against China,” she said, alleging that China is now Meta’s second-biggest market. “During my time at Meta, company executives lied about what they were doing with the Chinese Communist Party to employees, shareholders, Congress, and the American public.”

Wynn-Williams testified that Zuckerberg was fixated on earning profits, and she referenced corporate filings that add up to what she says is an $18.3 billion business the company has in China. She also alleged that Zuckerberg was so invested in the company’s relationship with China that he “learned Mandarin,” “had weekly Mandarin sessions with employees” and “traveled to China more than any other country.”

Other allegations brought to light included details around tactics used by Meta to exploit its younger users. Wynn-Williams testified that during her time there, Facebook would target 13- to 17-year-olds and could “identify when they were feeling worthless or helpless or like a failure” and would share it with advertisers.

“Advertisers understand that when people don’t feel good about themselves, it’s often a good time to pitch a product,” she said.

Meta has maintained as of Wednesday that it does not operate its business in China.

“Sarah Wynn-Williams’ testimony is divorced from reality and riddled with false claims,” a Meta spokesperson wrote in a statement to SFGATE. “While Mark Zuckerberg himself was public about our interest in offering our services in China and details were widely reported beginning over a decade ago, the fact is this: We do not operate our services in China today.”

Asked by Sen. Josh Hawley, the Republican from Missouri who chairs the subcommittee, why Meta was “so obsessed” with breaking into the Chinese market, she said that it boiled down to profits. She said Zuckerberg was aiding China with AI development during a time when China was trying to “rapidly” increase its own technological capabilities. Meta’s social media platforms are still banned in China due to censorship policies.

“It’s incredibly valuable to have the brightest minds in the world show you how that technology works,” she said.

“Mark Zuckerberg sold out America to China,” said Sen. Richard Blumenthal, a Democrat from Connecticut, during opening remarks. He continued, addressing Wynn-Williams, “You have your integrity. Mark Zuckerberg has lost his.”