Try unselecting Mobile data, battery, permissions, notifications under the Apps menu for any application that you don't care about, also under the battery menu, make sure that application is on the list of the apps that cannot run in the background and are on the deep sleep list. I don't know what to say about companies like Google, Amazon, Facebook, Samsung that get your money from one hand and steal your data from the other hand without your permission. You are picking on Facebook, I guess you have not noticed that you cannot even disable Samsung accessing your contacts, SMS, call logs, etc. Take a look at Samsung Cloud App and try to disable its permissions (they are all grayed out). I have nothing to hide but my personal data belongs to me and not Samsung which got $1200 from me for the N20U.