If you want to hide all public area also like Groups home etc you should limit the availability of this page via Studio->Pages area (every necessary page there->Settings) .

It is really a pain *** because one has to edit dozends of sites (f.e. Albums ne, albums favorite, albums lates, ... and so on for every app (Groups, Albums, Posts, Channels, ... .... ALL). Even better: you have to lokk in each one if there has to be changed the rights / visbility. Who invcented this? Did this one ever has had a web running and did not want to show everything to everybody???