However, TechCrunch reported that the messages were deleted from here as well. It will apply to all companies, including those outside of the EU.
The episode has sparked questions over privacy on the social media platform, and led to calls for tough new regulation.
After Zuckerberg's multiple interviews, the company's chief operating officer, Sheryl Sandberg, has also given an interview to NBC News' Today. European data protection authorities are supporting the British watchdog by providing evidence.
Wigand said that European Union data protection authorities will discuss over the coming days "a strong coordinated approach" on how to deal with the Facebook investigation.
"We have discussed this feature several times". But if you want the same level of security as Mark Zuckeberg right now, you may have to look beyond Messenger. The U.K.'s Information Commissioner's Office, which is leading the probe in Europe, is combing through the evidence it collected during a search of the offices of Cambridge Analytica on March 23. The news site said it has seen the receipts in the form of one-sided dregs of conversations and email notifications alerting some users that the Facebook CEO had been in touch.
Instead of using privacy as a guiding principle, Raymond said that it's more appropriate to use a model based upon the use of the data and the impact that using, sharing, re-sharing and potential loss will have on individuals.
It started with revelations that Cambridge Analytica, a data-mining firm, improperly accessed the private information of tens of millions of users to try to influence elections around the world.
Facebook's data policy - which was updated on Wednesday - states that it collects "the content, communications and other information you provide when you. message or communicate with others". The company did confirm the action, saying that a few sensitive messages were deleted owing to the increasing threat of hacking of the accounts. That data included details that were not meant to be shared publicly.
"We really believed in social experiences, we really believed in protecting privacy, but we were way too idealistic", she said.
Revealing plans for the Unsend button now could serve to dampen the backlash by making Zuckerberg look like a beta tester of the feature, and eventually normalizing Unsend as a common behavior. "We need to figure out what makes sense in different markets with the different laws and different places".
Health systems are notoriously careful about sharing patient health information, in part because of state and federal patient privacy laws that are created to ensure that people's sensitive medical information doesn't end up in the wrong hands.
"People are frustrated, feeling they were tricked to give away information as they engaged with activities on third-party apps", she said. They were also erased from the files contained in their data archives that Facebook allows users to download.