When I talk to people about it, there seems to be a general apathy around the privacy aspects. Most are of the opinion "why would someone other than my friends be interested in me and what I did on Saturday night?". I think the first wake-up call comes when their parents join facebook. Otherwise it's being turned down for a job without knowing why, getting fired for bragging about throwing a sickie, being harassed/stalked etc...
Im about to move out with my girlfriend, and my realtor checked my background with Facebook.
I only knew about this because that guy turned out to have gone to high school with my boss, and my boss told me.
Even though im a programmer, the only thing i do in facebook is add friends, it already affected me to just have an account there.
The effect was neutral to good..this time.