The Electronic Frontier Foundation have done some marvellous analysis of the way in which Facebook has gradually eroded it’s users privacy over the years:

Facebook’s Eroding Privacy Policy: A Timeline

In short, Facebook started out stating that your data would only be shared with other Facebook users, and then only those in groups you specified in your privacy settings.

Contrast that with the current policy whereby your name, picture, list of friends and more are considered public information (AS IF!) and much of your data is shared with Facebook’s partner sites whether you like it or not.

See Rixstep’s coverage for further redux.