Only touching the topic slightly:

In my school time we had a windows domain where everyone would login to on every computer. You also had a small private storage accessible as network share that would be mapped to a drive letter so everyone could find it. The whole folder containing the private subfolders of everyone was shared so you could see all names but they were only accessible to the owner.

At some point, though, I tried opening them again but this time I could see the contents. That was quite unexpected so I tried reading some generic file which also worked without problems. Even the write command went through successfully. Beginning to grasp the severity of the misconfiguration I verified with other userfolders and even borrowed the account of someone else.

Skipping the "report a problem" form, which would have been read at at least in the next couple hours but I figured this was too serious, I went straight to the admin and told him what I found. You can't believe how quickly he ran off to the admin room to have a look/fix the permissions.