The trusted systems which are part of the main UNIX cluster and have full access to the cluster file system. Only the members of the CCSG know the root password for these systems. When a new system arrives the owner has to decide if they want to have the root password and manage it, or have the system as part of the central cluster. It is possible if requested, to restrict access to a single user or group of users for any system in the cluster. Why We don't give out the root password Root password gives you access to any of the systems in the central UNIX cluster.
Root can become any users.
Therefor a root user can access, modify and delete anyone files or email. The root user can hide all of their actions. UNIX is a complex operating system some changes require modifications to several unrelated files, if you get it wrong it can take a lot of work to find what was changed, what was not and what needs to be done to fix it. To change the system name involves modification to several files on more than one computer. For several of the system files there is only one master which is copied to the rest of the network.