The more I use Facebook, the less I trust it. The more I see the granularity of information I've got about my friends, the more I think that privacy is underrated.
For example, one of the popular apps is "Hot or Not" where you rate your friends' appeal. Let me tell you something: there is almost nobody in my life who I would like to know my honest opinion about his hotness. Not my neighbor's son, not my boss, not my cousin, not that guy who hit on me last week, not Jeremiah Owyang, nobody. You tell me: is your best friend's husband hot or not? Neither answer is going to cut it on that one.
I'm using Hot or Not as an example, but it's any application. I don't want all of my "friends" to know who I poked, bit, or hugged, that I joined the AlAnon group, or that I saw the movie Clueless.
Assuming you could answer anonymously -- do you trust Facebook to keep the secret? Do you even trust yourself to click the right button to make it secret? There are tons of privacy and notification settings, and I've played around with a bunch of them. It's not really clear exactly what they do, and obviously, whatever is private to others is still not private to the Facebook backend or to the application writer (who is not Facebook and is not your "friend").
And then there are the friends you don't want. Those people you meet in everyday life that you can't avoid and you are polite to, but you pray they will not "friend" you because there is no way you want anyone to make any connection between the two of you. There is no tactful way to let them know that although your friends include people you have never met, they do not make the grade.
The upside of relinquishing your privacy is that you will get personalized advertising, customized to show you things you really might be interested in buying, rather than random advertising. Glory days!
Assuming you could get excited about any kind of advertising, the level of privacy you are giving up on social networking sites is less than comfortable. Nicholas Carr recently said, basically, that he wished he didn't know, but I wish it didn't happen.
I also recommend reading the cited blog by Nate Weiner. The bottom line is that Facebook isn't only recording what you on Facebook, but also what you are doing outside of Facebook.
Frankly, all of this freaks me out quite a bit. If I take this to the natural extreme, that means everyone I know can know everything I do when I am on my computer. All I can say is F2F meetings are going to become an increasingly important part of my life.