When I was first in school -- and by school I mean graduate school -- the school had a IBM running VM/CMS for general computing. Everyone had an account. In those days you could set up virtual disks to be shared and there was a mount command in exec 2 that let you mount a shared volume given the password. A lot of people would put the mount command and password in an executable script that would run at login. When a professor or admin gave you credentials to a volume, it might have a script in it with credentials for another volume.
I wrote an exec2 program to sift through the files in a volume looking for shared volume mount commands, then recursively mount and search any found volumes. It seemed to work pretty well.
At that point I showed the script to a random undergrad and forgot about it. He was later expelled and arrested.