On Facebook, Twitter, etc. even if you delete your post it is still there. As most of you know it is still on their database, the only difference is that it has some sort of deleted flag and you can't see it. Companies have been doing background checks for years using third party resources. In the near future, if not already, these third party companies will pay Facebook to pull all data on your profile and analytics associated with it, regardless if you have "deleted" it or modified it.