Well its not… there are numerous articles talking about back doors in applications and every layer of the OSI model. You can look up many applications , for example candy crush or angry birds , fakebook whatever bullshit crap app you download for free. The user gives permission to microphone, camera, contacts, gps etc… Look at the tracking going on with the fakebook app for android and iphone. You are tracked even if you are not a user of fakebook. Verizon install the app and you can't delete it from your phone.