Sometimes it is necessary to put restrictions on users, if you have a computer to the public or used by many people. For example a library, we can not allow anyone to put their taste or change certain settings. In your Gnome desktop environment there is a tool called Pessulus that will control these profits that can manage users.
General, allowing us to configure access to the command line, printers and the ability to save files.
Panel, where you can block access to applets and controls such as blocking off and restart the computer.
Browser, allowing us to configure all the properties that can change the user’s browserGnome Desktop, which controls user sessions.
From this application you can control the vast majority of the options for Gnome.
To install just have to type in your terminal:
$ sudo apt-get install pessulus (or equivalent depending on distribution)