Re: How secure *IS* your system
Ah the memories of sixth form and BBC/Archimedes networks.
In the lower sixth, we just had normal (non-priv) accounts, but the network manual was to be found in the (always open) server area (aka the walk-in cupboard at the back of the classroom with the server on one of the shelves around the edge of it). And it had full details of all the OS commands, including how to "write" them in assembler.
Hence almost all of the priv user commands ending up being available via self-written versions. And a surprising amount of them actually worked perfectly, even without the account actually having any elevated privs.
And in upper sixth, when we started doing A-level projects that (mysteriously) needed priv users, we got them.
Queue two of the lower sixth, who hated one another, independently coming to me and asking for the password for the other's account.
So I did what any self-respecting BOfH would do, and swapped their account passwords over, without revealing to either what their "new" password was.
Mexican stand-off ensued, with the two trying to find ways to extract their new password from the other without revealing their own password.
Teacher walking in half-way through, stood there for a while watching before intervening. Then afterwards took me aside, waggled a finger and said mock seriously "don't do it again...", only spoiled by the rather huge grin on his face before wandering away into aforesaid server cupboard from which much pent-up laughter was then heard.