Is there a reason to believe, given how little we trust Facebook, that deletion and deactivation are different things? I've built multiple consumer web apps an

Is there a reason to believe, given how little we trust Facebook, that deletion and deactivation are different things? I've built multiple consumer web apps and if there's one rule, it's that rows are never really deleted from a database. Not to mention backups, caches, Google crawls and so on. I'd worry that the naive consumer thinks they can post embarassing content to Facebook, delete their account, and somehow believe it will never be found again.