Facebook users who don’t know they are sharing
I'm pretty sure all this Facebook stuff will blow over soon enough. Most people have changed their privacy settings by now. The rest don't really care. Some people though simply have no clue that what they're sharing with their inner circle is out on display for anyone to see. Openbook uses the Facebook search API to show these users. Search for a term or phrase and see the status updates of public profiles.
The above is one of the search results for "cheated test." A lot of the first results are just people playing around with the system, but scroll down some, and you'll get a good taste of messages many probably don't want others to see.
How about a search for hate job?
At least if you get fired because your employer sees your status on Facebook, you won't have a job to hate anymore.