Here comes Openbook. In the same sort of vein as PleaseRobMe, which showed potential issues with telling people where you are constantly, Openbook lets you search status updates for all sorts of information. To show the potential embarrassment possibilities, their default search when I visited the site was “rectal exam.”
Obviously, this is just a simple API call, but it shows the kinds of things that are available to just about anyone. By this point, everyone should assume that anything posted on Facebook will not be kept private.