The current direction Facebook has taken is rightfully seen as hostile to individual privacy. But remember that Facebook was was only moderately interested in providing a private space online anyways. The make money in selling their data to marketing organizations. They (Zuckerberg) talk about how sharing and being open in personal data is good for society, yet they have shown that their corporate privacy is important, and I’m sure Zuckerberg isn’t sharing all his personal information to the world either.
Now don’t get me wrong; Facebook is providing a good public space for people, and using it to make money. This is a ‘win-win’ situation for a sales team. Everyone gets what they want. However, Facebook has two fundamental problems that they have yet to address. The first being that they regularly changed their privacy rules, confusing the people using Facebook into sharing more information then they knew. They add on privacy controls to change that but by that time users find these controls, their information has already been made public and thus sell-able by Facebook. Users are not given the chance to say no first. (Likely because they would say no by default given the chance.)
Now, given all this that I said, here is the reality: If you go to blogger or wordpress and start a blog or use Twitter, then by default everything you post is available online to everyone. You have to assume Facebook is the same. People have assumed that Facebook is between a public blog and private email, but in reality it is not. And Facebook is not going to change to make it that way. Google is more careful about privacy concerns with email, and for now, they have been good about it. And there are blogging software that allows you to setup a ‘friend’ list of people who are the only ones you allow to see your blog. Facebook is less private then that. And they make a compelling product to convince you to use it in a public way. But with any online communications, do not post, email or IM assuming its private. If you need private communications, use real encryption for your IM or email. Otherwise you are basically writing on a bulletin board.