Facebook executives tend to favor open access to information, meaning information you think is private will slowly become public. Facebook gives its users the option to lock things down, but users need to be aware of their controls, how to use them and how to prepare for future privacy changes. Facebook has not and will not make information obvious, and that’s where this free guide comes in to help you understand the privacy of Facebook users and prepare for the inevitable changes to the site’s privacy controls and privacy policies.
Source: https://thehackernews.com/2011/01/unofficial-guide-to-facebook-privacy.html