This is what happens when you modify any of the information in your Facebook profile or when you decide to deactivate or delete your Facebook account.
You may change or delete your Facebook profile information at any time by going to your profile page and clicking "Edit My Profile." Information will be updated immediately. While you cannot delete your date of birth, you can use the setting on the info tab of your profile information page to hide all or part of it from other users.
If you want to stop using your Facebook account you may deactivate it or delete it.
When you deactivate an account, no user will be able to see it, but it will not be deleted. We save your profile information (friends, photos, interests, etc.) in case you later decide to reactivate your account. Many users deactivate their accounts for temporary reasons and in doing so are asking us to maintain their information until they return to Facebook. You will still have the ability to reactivate your account and restore your profile in its entirety.
When you delete an account, it is permanently deleted. You should only delete your account if you are certain you never want to reactivate it. You may deactivate your account on your account settings page or delete your account on this help page.
…Limitations on removal. Even after you remove information from your profile or delete your account, copies of that information may remain viewable elsewhere to the extent it has been shared with others, it was otherwise distributed pursuant to your privacy settings, or it was copied or stored by other users. However, your name will no longer be associated with that information on Facebook. (For example, if you post something to another user’s profile, and then you delete your account, that post may remain, but be attributed to an "Anonymous Facebook User.") Additionally, we may retain certain information to prevent identity theft and other misconduct even if deletion has been requested.
[Elliot Schrage from Facebook sent this information via an email message.]