Zuckerberg vows action to bolster Facebook's data privacy

“We also made mistakes, there’s more to do, and we need to step up and do it,” Zuckerberg said in a Facebook post on Wednesday.

The statement was the first time that Zuckerberg has spoken out since The New York Times reported over the weekend that Cambridge Analytica, a political consulting firm that provided voter-targeting services to Donald Trump’s presidential campaign, improperly obtained data on 50 million Facebook users.

Facebook has faced a backlash as a result. Politicians in the United States and Britain have called for Zuckerberg to explain his company’s handling of user data, and state attorneys general in Massachusetts and New York have begun investigating Cambridge Analytica and Facebook. A movement calling on people to delete Facebook has also gathered steam among users who have lost confidence that the company is trustworthy in collecting — and safeguarding — their data.

Inside Facebook, even staunch supporters of Zuckerberg have described a tense atmosphere. As criticism of the social network’s larger role in the 2016 presidential campaign has continued to fester, some employees have sought to transfer to other divisions, such as the messaging app WhatsApp and the photo-sharing platform Instagram, calling their work on Facebook’s main product “demoralizing.”

Zuckerberg spent part of the past week hunkered down with a small group of engineers to discuss how to make information on Facebook’s users more secure, and to potentially give them more control of their data, according to two Facebook employees who declined to be named because the proceedings were confidential.

Among the steps Zuckerberg said Facebook was taking: an investigation of apps that had access to “large amounts of information” from the social network before it made a policy change in 2014, restricting developers’ data access to the social network, and more disclosure about the apps that people have used and how to revoke the apps’ permission to use the data.

“We have a responsibility to protect your data, and if we can’t then we don’t deserve to serve you,” Zuckerberg said.