What happens to content (posts, pictures) that I delete from Facebook?
When you delete something you shared on Facebook, it is permanently deleted from your Facebook account. It's deleted from our servers and backup systems, so we're unable to retrieve this deleted content.
However, Facebook may keep service-related information about your account, like IP address logins or email changes on your account, to protect your security, prevent abuse, and improve our services. This information may only be fully removed when you permanently delete your account.