Interesting article about Facebook at the WSJ, specifically about whether or not students realize how much information they are giving out with their profiles. Of course, most of the examples are on the extreme side and I think it is a bit over the top to make blanket statements about the dangers of the site when a very small number have had any problems.
That being said, I do think that anyone working on a social networking site of any kind should consider privacy and security high on the development list. You need to walk a fine line between wanting as much information from users as possible in order to help find different types of relationships and respecting the need for the user to have privacy.
Perhaps a way to do this is to have layers of accessible information. The outer layer just has basic data which isn't especially deep but should be useful. As a person becomes more trusted to a user, the more information is available to them. This type of thing is modeled in real life in the sense that there are many things you will only tell your friends which you would never tell someone you just met.
Technorati Tags: socialnetworks, facebook, privacy