Matt's analysis was thorough and revealing. It is summarized by a series of charts depicting user growth and information sharing on Facebook, at multiple points in time: 2005, 2007, 2009 and early 2010.
Earliest "snapshot" of Facebook user privacy 2005
Matt's article has all six charts in chronological, as well as a complete explanation of his methodology, including data collection details. It demonstrates very clearly the dramatic increase in level of exposure of private data for Facebook users.
Personal data and privacy status as of April 2010
Please note that these charts are part of a work-in-progress and may be updated at any time. They are reproduced here* with specific permission from Matt McKeon but are not Creative Commons licensed and may not be further reproduced except under the limited usage terms on Matt's website.
This real-life image via fffound is well-matched with the conclusions one may draw after reviewing Matt's analytic work.
Also have a look at these eyebrow-raising product offering inspired by Facebook that I noticed on Amazon. (I am not endorsing them, nor encouraging anyone to purchase anything; I included them for amusement purposes only).
Keep in mind that this is a small sampling of Facebook-related books from Amazon.com. Much more is available. I admit, I chose the most sensational-sounding of the bunch.