On a fresh installation of Trisquel Mini 7, the user lacks permission to graphically control the power and network.
If I try to shut down from LXDE's menu, I am not permitted. If I try to select a network using the NetworkManager applet, I am not permitted. However, if I log out, I am able to shut down via the login manager.
I am not able to do these things from the command line either.
$ nmcli dev wifi con my-ssid password mypassword
Error: Failed to add/activate new connection: (32) Not authorized to control networking.
This has already been reported in
https://trisquel.info/en/issues/12007
Which contains a bypass you can use so you have the required permissions.