A second Facebook whistleblower says she's willing to testify before Congress and that she's shared documents with a US law agency

• The former Facebook employee Sophie Zhang is willing to testify before Congress, she told CNN.
• Zhang said she'd shared documentation about "potential criminal violations" with US law enforcement.

Sophie Zhang, a former Facebook data scientist who went public with her criticisms of the company in September 2020, has told CNN she is willing to testify before Congress.

Zhang also said on Twitter on Sunday that she had provided a US law-enforcement agency with "detailed documentation regarding potential criminal violations."

When asked by CNN, Zhang did not say which agency she gave documents to. An FBI spokesperson declined to comment when contacted by CNN.

"If Congress wishes for me to testify, I will fulfill my civic duty, as I've publicly stated for the past half year," Zhang said in a tweet Monday that linked to her CNN interview.

Speaking to CNN, Zhang said she was encouraged by the apparent bipartisan support for action against Facebook after Frances Haugen, another Facebook whistleblower, testified about children's safety on Facebook and Instagram in a congressional hearing on October 5.

Zhang was fired from Facebook in August 2020, but before she left she posted a 7,800-word memo detailing how she believed the company allowed authoritarian regimes around the world to manipulate its platform.

"I have blood on my hands," Zhang wrote in the memo, which was obtained by BuzzFeed. Zhang wrote that she was officially being fired for "poor performance."

As well as posting the memo internally, Zhang uploaded it to her personal website, and in July she told MIT Technology Review that Facebook had issued a complaint to her hosting server and that her website was subsequently taken offline.

In a statement to Insider a Facebook spokesperson said: "We have invested $13 billion in the safety and security of our platform and have 40,000 people who review content in 50 different languages working in 20 locations all across the world to support our community. We have also taken down over 150 networks seeking to manipulate public debate since 2017, and they have originated in over 50 countries, with the majority coming from or focused outside of the US. Our track record shows that we crack down on abuse abroad with the same intensity that we apply in the US."

"As a platform used by so many around the world, we know people feel passionately about our products and with this impact comes scrutiny and responsibility. So while we think it's critical that we're held to account, we also think it's important to add context about the work that different teams do and respond when the work of thousands of people at Facebook is being mischaracterized," the spokesperson added.

Haugen said in her October 5 testimony that Facebook under-resourced teams and tools that were looking for abuse in languages other than English.

Facebook CEO Mark Zuckerberg published a statement last week saying Haugen's characterization of the company was a "false picture."