[Pkg-utopia-maintainers] Bug#774051: [network-manager-gnome] does not save config for networks to user directory

[Alex Goebel]

That is (was? not sure what the systemd and gnome people have decided 
for us) the intended behaviour. The network setup is part of the system 
configuration, not owned by a normal user.

Of course the problem you describe is real, and the solution is full 
disk encryption (FDE). It's offered by some disks (pro: hardware, easy 
to use, everything encrypted, even /boot. con: manufacturer backdoored), 
or software solutions like cryptsetup/dm-crypt.

FWIW, there is potentially a lot more information in /etc, /tmp, 
/var/tmp, etc. which you wouldn't want an attacker to get access to, so 
FDE is pretty much a must if you care about such things.