Check your Facebook privacy settings
This interesting app at http://zesty.ca/facebook/ lets you see what is publicly available through Facebook's new data APIs. Facebook's latest privacy settings are a real mess, so I think it's important that people have some transparency into what is actually being made public.
Still, after a fair amount of work, it does seem possible to make most of your profile private, at least as exposed through this API. Here's what you can see for my profile after I've made some rather restrictive changes to my settings: http://zesty.ca/facebook/#/dfjones