Less than a week after reports that Facebook plans to more broadly roll out end-to-end encryption across its messaging features, a trio of privacy experts who have criticized the company’s handling of user data in the past announced that they are joining the company.

Nate Cardozo, formerly the senior information security counsel for the nonprofit Electronic Frontier Foundation, announced in a Facebook post that he would be joining the company as a privacy policy manager for WhatsApp. Robyn Greene, a senior policy counsel and government affairs lead for the Open Technology Institute, tweeted that she’d be joining Facebook as a privacy policy manager working on “law enforcement access and data protection issues.” And Nathan White  joined Facebook this month from digital consumer rights group Access Now, the Information reported.

A Facebook spokesperson told VentureBeat that the company is hiring more experts to improve the company’s privacy products, tools, and processes and said that the goal is to bring in people who can “offer new perspectives and can help push us toward better approaches to privacy challenges in the future.”

The three are joining Facebook from organizations that have advocated secure communications and/or more user control over how data is handled — issues that have been particularly fraught for Facebook.

Cardozo’s hire is especially notable, given that he’ll be leading privacy policy at WhatsApp. As the New York Times reported last week, Facebook plans to tweak its messaging infrastructure so that users can send messages to others across any one of the company’s family of apps, even if the senders themselves are not on that app. Facebook plans to make the necessary infrastructure changes within the coming year.

That would be a particularly big shift for WhatsApp, which currently enables end-to-end encryption by default. However, as part of the change Facebook also plans to roll end-to-end encryption out more broadly across all of its apps.

The plans have reportedly upset some WhatsApp employees, who aren’t satisfied with the answers CEO Mark Zuckerberg has given them about why he wants to unite the messaging services.

It’s also unclear what these changes would mean for user data storage — could users opt out of sharing data with Instagram or Messenger if they don’t use one of those services? How would Facebook notify users about any changes? These are questions that members of the privacy policy team will likely be called upon to answer.

As the Information notes, the new additions to the privacy policy team also come as many members of Congress have become more critical of Facebook over the past year and a half, calling on Zuckerberg to testify in front of both chambers of Congress to explain how Cambridge Analytica obtained data from users without their consent and how Facebook failed to stop Russian interference during the 2016 U.S. elections.

All three new hires have been openly critical of Facebook in the past — the Information reports that Greene called on Zuckerberg to testify in front of Congress before he was officially requested to do so. The report also pointed out that White has argued additional congressional hearings with tech company representatives should include “civil society or consumer protection groups.”

Cardozo and EFF called on Facebook and other tech companies to be more upfront with users about why the company removes certain posts. In 2015, Cardozo wrote an op-ed for the San Jose Mercury News criticizing Facebook Pixel and saying that the company “confuses consumers for profit.”

“If you know me at all, you’ll know this isn’t a move I’d make lightly,” Cardozo wrote on Facebook today. “After the privacy beating Facebook’s taken over the last year, I was skeptical too. But the privacy team I’ll be joining knows me well, and knows exactly how I feel about tech policy, privacy, and encrypted messaging.”