Facebook has built up a formidable store of data on its five hundred million users, including billions of status updates, comments, photos and videos. Now the company is setting that data free, by allowing users to download a file that contains all of the information they’ve uploaded to the site. This change shows that the company is responding to the complaints of advocates concerned about how Facebook handles the data it collects. But it could also make easier for a new social network to get started.

This change was one of several announcements made yesterday to address common complaints about Facebook. Privacy advocates have criticized Facebook for making it difficult for users to retrieve their data, for how the company shares data with third parties, and for making it difficult for users to close an account. The company has also come under fire for making changes without fully educating users about what those changes mean, and for lacking ways for users to control who sees the information they post.

Facebook also announced changes to the way groups work on the site, which should make it easier for users to post information intended for certain people. When a user posts information and wants to restrict it to a group, Facebook’s algorithms will guess at who should be in the group–partly drawn from groups that have been created by others–but the user has control over who to select. Facebook also launched a dashboard that lets users see what information third-party applications are using, and when those applications last requested data.

Letting users download all their data could be the most important change, and it could have unintended consequences. A new social network–such as a the one Google is rumored to be building–could use that data, with users’ permission, to automatically add information to new users’ profiles.

It may seem strange for Facebook to open up one of its most valuable resources this way, but the company is obviously working hard to repair its image. And other companies already offer similar services, for example Google’s Data Liberation Front.