I can attest also that Facebook definitely does track everything and ignores settings both within its own app and within iOS. I have the privacy settings that are buried deep within the app configured to the bare minimum, and I have all the typical privacy settings from within iOS configured to the bare minimum as well, but Facebook makes it very clear through their very targeted advertisements and their very targeted location-based suggested friends that my settings are being ignored. I don't know how Apple allows it...I guess because it's so deeply integrated into iOS it has extra permissions that are probably buried within iOS' and Facebook's terms that we all agree to but don't read. But that's for another thread.