The furor that has arisen due to the
change of FB users privacy settings (including changing previously set privacy options to 'Y' when they were 'N' and so on...) is just the tip of a proverbial iceberg.
Those of you who use social networking sites and have a 'I have nothing to hide' or 'my stuff is boring, someone would find little of interest' are simply fooling themselves. You SHOULD be saying 'I have nothing I wish to disclose' or similar. The use of a computer to draw conclusions from a host of data available is just a simple step forward and, with increasingly new and clever ways of manipulating data, can draw out some very presumptive (and potentially damaging) conclusions with regard to you as an individual.
There was a story a while back of (I believe) an NYT journalist doing research on a TiVo and the services it offered. The device to selectively view channels and programmes that match/ed your viewing habits. As part of the research he looked at the range of 'interest specific' programming. He looked at home/interior decorating programmes, a classic movie channel (Clark Gable, Spencer Tracy genre), and holiday travel programmes. After he had done the research he kept the TiVo and, due to a flaw in the algorithm for profiling preferences, for months after the service had built his profile as matched against others with the same viewing habits, the same locality, status and so on... and determined that he was gay, into hard-core gay porn, and also into spiritual programmes (tarot, astrology, palm reading, and voodoo). It took several months of watching things like Rambo, hunting and fishing channels, and Nascar before being identified as the heterosexual male he actually was.
Amazon, iTunes, and many other sites, make recommendations based upon your previous purchases and or what you viewed/listened to. All of these services are based upon a simple bit of profiling and the decisions you made at a specific time or date. The data you provide them with is transparent in that any decisions made are not necessarily representative of you. You could for example be making purchases on behalf of another person or a gift that does not represent your normal tastes or buying choices. However, the analysis of the data is against you.
Normally these anomalies work themselves out over time so the 'NASCAR 2010 Fanzine' subscription you bought for your nephew Eddie does not permanently label you as a double-wide, tobacco chewing redneck... and you can go back to your macrame kit or poodle shampooing.
