My experiences with services that have posted things to my FB timeline without prior permission make me very reluctant to trust any service that asks for Facebook integration. Luckily no app has ever posted personal sensitive information but several have polluted the timeline with information I don't want there. Irrelevant stuff like that time Slideshare posted about me downloading my own presentations as PDF. Or when I followed a question on Quora. Permissions I would never have given had I been asked by the websites in question.