Facebook has gotten a bit of unwelcome publicity recently about its changes. There is quite legitimate concern about privacy, but there is also a rather large amount of hypocrisy.
For example, a local TV station did an expose on Facebook on the same news show on which they promote their spiffy new website on which people can upload photos and text. The security and privacy settings on their spiffy new website are as close to non-existent as possible. No e-mail verification, no information as to whether or not the user-chosen password is encrypted (people tend to re-use passwords so it's quite likely that more than a few PIN codes are used), and in their on-air promo, the nifty step-by-step registration process is truncated to not even mention accepting their Terms of Service.
If you are concerned about Facebook privacy, there are two immediate steps you can take.
First of all, review your privacy settings (the Account menu in the upper-right of most pages, then Privacy Settings and then Profile Settings. The safest setting for all of these is Only Friends (it's in bold in the list). What seems to be causing the problem is the Everyone setting which means what it says. As Facebook puts it in Privacy Settings for Applications & Websites:
When you visit a Facebook-enhanced application or website, it may access any information you have made visible to Everyone (Edit Profile Privacy) as well as your publicly available information. This includes your Name, Profile Picture, Gender, Current City, Networks, Friend List, and Pages. The application will request your permission to access any additional information it needs.
To turn off the Instant Personalization Pilot Program which seems to be causing some of the grief, just got to that item at the bottom of Account -> Privacy Settings -> Applications & Websites. There's a checkbox at the bottom of the page--uncheck it.
You can download a screenshot attached to this post.