Hello,
I would like know if it’s possible to set the gnome desktop so that only user’s that are part of a group can use gnome desktop. So for example the users by default can use only text mode, unless I change the permissions for the user. In other word’s: when users login to the computer, he only gets text mode. If the administrator gives him the permissions to use the desktop, then after login he can use the gnome desktop.
I hope you can understand waht I would like to do.
Greetings Jure
Seeing you do want to boot into GUI mode (for the GNOME users) maybe thinking along the lines of giving the console users an .xinitrc file in their home directory that only opens/runs a terminal console but does not start the DE.
Removing the file from a users home directory will revert to normal login.
If you set readonly rights to the file only root can remove the file.
This does not restrict them from running commands in the consloe… and seeing X is running…
So you might want to consider some kind of kiosk framework so users can’t fiddle around in the terminal to get the GNOME environment that way.
Also, (afaik) files in the usr directory are usually for the X environment.
An idea is maybe making a separate user group that the console users get assigned as default (instead of the user group) that does not have any rights to the /usr folder and only rights to older folders it needs for users to be able to do their thing (/bin /etc/ /lib … ect).
Another option is to always boot up into console mode and have a user login script fire up their X environment at login…
I’m sure others have better ideas… but just venting some thoughts.
Let us know how you go! 
Cheers,
Wj
Magic31 thanks for the ideas. I will try different stuff and will keep you posted.
Greetigns Jure