Sarah Wynn-Williams, Facebook’s former Head of Global Public Policy, testified before the U.S. Senate today about the company’s relationship with China.

According to Wynn-Williams, the company now known as Meta worked directly with the Chinese Community Party (CCP) to “undermine U.S. national security and betray American values,” she said.

She alleges that Facebook created custom-built censorship tools for the CCP, which gave a “chief editor” extensive power over content moderation to the point that they could choose to shut off service completely in certain regions of China or on certain dates, like the anniversary of the Tiananmen Square massacre.

Meta denied Wynn-Williams’ allegations.

“Sarah Wynn-Williams’ testimony is divorced from reality and riddled with false claims,” said Ryan Daniels, a Meta spokesperson, in a statement to TechCrunch. “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.”

Wynn-Williams’ testimony was highly anticipated. In March, she published a book about her time at Facebook called “Careless People: A Cautionary Tale of Power, Greed, and Lost Idealism.”

The day after the book was published, Meta won an interim decision from an arbitrator, which said that Wynn-Williams violated a non-disparagement clause that she signed when she left the company. But Meta’s desire to limit the book’s reach seems to have had the opposite effect — now, the book is No. 2 on The New York Times Best Sellers list under non-fiction.

Meta told TechCrunch that the arbitration order does not prohibit her from speaking to Congress and that the company does not intend to interfere with her legal rights. The company also said it’s not a secret that it does business in China.

Toward the end of Wynn-Williams’ tenure in 2017, Facebook had launched a photo-sharing app called Colorful Balloons in China, as well as an app called Moments. Meta points out that this has been previously reported and that it discloses in government filings that it generates advertising revenue from China, even though its services like Facebook and Instagram are banned there.

Per Meta’s own 10-K filing, it made $18.3 billion in revenue for 2024, up from $13.69 billion and $7.4 billion in 2023 and 2022, respectively.

Wynn-Williams claims that Meta’s relationship with the Chinese government runs deeper, though.

She shared documents with Congress, and Senator Josh Hawley (R-MO) showed some redacted versions of these documents in the hearing.

In one email, it appeared that Facebook executives had discussed granting the CCP access to user data from China and Hong Kong.

“Facebook appears to have been willing to provide the data of users in Hong Kong to the Chinese government at a time when pro-democracy protesters were opposing Beijing’s crackdown,” Senator Richard Blumenthal (D-CT) said, then asked Wynn-Williams if that is true. She said it is.

“As part of the censorship tool that was developed, there were virality counters — so any time a piece of content got over 10,000 views, that would automatically trigger it being reviewed by what they called the chief editor,” she said. “What was particularly surprising is that the virality counters were not just installed, but activated in Hong Kong and also in Taiwan.”

Senator Blumenthal pointed out that Zuckerberg had previously denied under oath that Facebook had built censorship tools to enter the Chinese market.

Wynn-Williams added that if Meta were to share Chinese user data with the Chinese government, from a technological perspective, she doesn’t think there would be a way to avoid sharing user data from Americans who had interacted with Chinese users.

She also claimed that Meta had briefed China on developments with various technologies like AI and facial recognition.

“The greatest trick Mark Zuckerberg ever pulled was wrapping the American flag around himself and calling himself a patriot, and saying he didn’t offer services in China, while he spent the last decade building an 18 billion-dollar business there,” Wynn-Williams said before the Senate.

“And he continues to wrap the flag around himself as we move into the next era of artificial intelligence,” she added.