I think people want the ability to easily control what information is and isn't private. While Facebook offers a lot of control -- you might even say a confusing amount for most people -- it's still doing its best to encourage you to share early and often.
If you can't easily determine how someone wants a particular piece of information to be treated, you should assume it is private, not that they want to share it with the world. The latter is the assumption Facebook is making and Zuckerberg was defending.
What people really want is not what Facebook is giving us. As Read Write Web's Marshall Fitzpatrick points out, Facebook's popularity stems in part from how carefully it protected its members' information -- at first limiting access to college students, then just to your networks of friends. Now it seems to have forgotten all of that, to its detriment.
Why? In a word, money. You can't easily monetize data that's private. The more data you can share with the world, the more revenue you can generate. Facebook isn't trying to give users what they want or to conform with "social norms." It's trying to make a buck out of each and every one of its 350 million users, over and over again. Nothing wrong with that, except perhaps how you go about it.
Do you care about privacy? Has a "personal information leak" online ever come back to haunt you? Share your thoughts below or e-mail me: firstname.lastname@example.org.