How to completely hide stuff from a user?

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http://unix.stackexchange.com – I want to let some of my friends access my computer by making them user accounts. They will mostly access my computer by sftp and ssh, but they could also sometimes access it at my home. However I don't want them to be able to see all my file (not my personal files from my home directory, I mean files that reside outside of the user directory, like etc, lib...) I asked the question recently: OpenSSH, chroot user: Root need to own the user directory, is there any consequence? And the awnser that was given to me was that if I chroot the user, I will need to create a complete environment for e (HowTos)