That is one thing lacking in Nuke. A good group management system.
NSN
http://www.nukescripts.net has a Groups addon for Nuke, but it doesn't really do what I thought it would.
The perfect setup would be a Group management system where you can add users to certain Groups and then those Groups can be grasnted permissions to access certain modules. Thus the control over WHO can access a certain module in Nuke.
mikem