For us it comes down to two things: fair choices and best intentions. In our view, Facebook doesn't do a good job in either department. Facebook gives you choices about how to manage your data, but they aren't fair choices, and while the onus is on the individual to manage these choices, Facebook makes it damn difficult for the average user to understand or manage this. We also don't think Facebook has much respect for you or your data, especially in the context of the future.
From the Upcoming ueue, submitted by nmiller.
http://www.groovypost.com/howto/security/permanently-delete-your-facebook-profile-account/
The point is, FB is ostensibly a tool for connecting to your friends (and/or classmates or workmates). There's all kinds of innocuous information you can fill in, from your religion to your favorite books.
And yes, the understanding was that this was to tell other people about yourself, especially people you've just met in class, and let them find out things about you that might not otherwise come up in conversation for some time.
And maybe, just maybe, some people would like to put up lots of information about themselves and-- gasp!-- only have it appear to their chosen few (or many). Currently, anything you "like" (which applies to basically everything) will appear in your public profile with no option for limiting that. My boyfriend noticed that in a Google search for his name, posts that he had made to some of those pages came up as well. It shouldn't come down to "Facebook or no FB" just to have the option of some minor privacy (that FB used to afford its users but has been slowly stripping away, and good riddance).
Have you typed your name in Google recently? The amount of information that can be gleaned that way is easily as disturbing as knowing your personal information is being hustled off by the social networking sites.