Yeah the "data" thing is just a rule of thumb, users aren't usually interested in data in and of itself, but how they can use it.

Creating a tool that is an expose' of how you are having your privacy violated by Facebook is a noble idea but you run the risk of creating a site that is creepy and discomforting. You run the risk, basically, of people shooting the messenger. So, tread carefully :) For example, if you're going to go that route, make sure people can only see their own results, not other peoples' (and, most importantly, they realize this is the case), and that you provide overt and helpful information on how to lock down their privacy. (Nobody likes to feel helpless, especially immediately after realizing they've been exposed.)

To me a much more attractive proposition is to figure out what parts of the W|A project (or things you've done) are non-obvious but valuable applications of non-trivial data analysis of the Facebook graph that many people would enjoy. Building an experience like this would avoid the creepy "I'm just telling it like it is" factor as well as open up the possibility to sharing each others' results which takes the experience to another level.