If you live in Europe, then you have the right under a European data protection law to request a copy of all information stored about you on any given service. In the case of Facebook, you can demand such information via the Personal Data Requests form.
via Facebook stores up to 800 pages of personal data per user account | Geek.com.
Facebook is relatively new and the average person doesn’t value their privacy — thus, Facebook has been able to acquire a huge amount of personal information on each member. Organizations might soon value privacy and see value in the data they generate, in which case local highly available onsite (or perhaps offsite) SANs will become a useful investment. Associations without a central authority (i.e. Facebook) might become desirable. It is however not feasible for an average person or small business to run their own web server. They should, however, be in complete control over the data their web site generates. Users of Facebook have no control over the dissemination of the data they and their connections generate.