[femto]

I recall the same type of network and exactly the same situation here in Australia, with a student locking everyone out. From memory, despite appearances the password system was essentially an honour system, involving one computer being the "master terminal" (try keeping kids away from that keyboard) and even then there being ways around it. I think the offending student got a stern talking to and a day off school. We taught ourselves quite a bit on that network, and the teacher in charge of it was quite happy to admit that his knowledge could take us only so far, before self-learning had to take over.