i used to own a few websites myself, i never did this but anyone with an app or website could pinpoint everything about you in just a few minutes, also selling of your info without you knowing happens on just about all websites, i didn't have the heart to do that to anyone so i just left that part alone. your emails are sold in bulk to anyone who wants to pay for it. If your going to delete facebook you might want to think about everything else you are on too realistically. You think facebook is bad honestly google is number 1 id watch out for. twitter amazon ect.