Facebook lets people download absolutely everything it knows about them, says Mark Zuckerberg

It is relatively easy to download a file of all of Facebook's information – but it's not clear that includes everything

Rep. Markwayne Mullin (R-OK) (L) greets Facebook co-founder, Chairman and CEO Mark Zuckerberg before he testifies to the House Energy and Commerce Committee in the Rayburn House Office Building on Capitol Hill April 11, 2018 in Washington, DC (Chip Somodevilla/Getty Images)

Facebook users can download everything that the site has collected about them, Mark Zuckerberg has said.

The site offers all of its users the ability to download a file of data that it has collected about them. But some have worried that it doesn't actually contain everything it has kept about them.

Many people, for instance, fear that Facebook is tracking their browser data as they move around the internet and off the site. But that data doesn't show up when people download their data.

Mr Zuckerberg suggested that data was not included because it was not being collected, when he was asked about what is contained in the information that users can download. When asked whether there is information that Facebook has – or inferences Facebook has made on the basis of information – that would not show up in that file, Mr Zuckerberg said that there wasn't.

"I believe that all of your information is in that file," he said.

Users can download the files from the Facebook website, by clicking on the little arrow in the corner and selecting settings. From there, users can click "Download a copy of your Facebook data" and the site will put all of it into an archive.

Some users were shocked to find when downloading that data that it seemed to be collecting some incredibly personal information, including details on messages and phone calls that they had made, going back many years.

But it has also been suggested that some of the information Facebook has on its users is being held back, and not put into those files. It does not include any information about what sites people have visited, for instance, as the committee grilling Mr Zuckerberg pointed out.