I also used not to care, because I used to think that "I don't put that much information on it". But it always said data, but not which data, now I know it buys data from other to cross it, don't know which data they buy and don't know what kind of information they are able to get when they do this. This is what we are only now understanding that they are doing and what is possible to do with this. And of course, Facebook say the least minimum necessary to keep profiting with no problems. Hence I don't see how we can expect people to really know what Facebook does.