Been there, done that, had the stitches pulled
Oh, this story definitely rings a bell.
Back around 1988 or so, I worked in a shared lab environment. There was no network, and it was very much "every man for himself" development.
Every group had its' own naming convention, naturally. And this was in the days of DOS, with 8.3 file and directory names. So, I created a root directory DEVTEAMS, under which I'd put a READ.ME file stating that the subdirectories could be used by anyone. I figured that way, anyone who backed up the DEVTEAMS directory would back up every group's work, and we'd have multiple backups. Backups were done with floppies, which were painfully slow, so I tried to compartmentalize all the development into one folder tree.
One machine had both a transputer card (remember those?) and a special video card. My group was doing video work; another group was doing work on the transputer, so we created \DEVTEAMS\VIDPROJ for the video project. I even created \DEVTEAMS\TRANSPTR for the other team, though they never used it.
Now, for those unfamiliar with transputers, they are/were massively parallel processors, which used a non-sequential language called OCCAM to take advantage of this. However, because of this parallelism, source files were not stored sequentially. A 12 line C program could be "hello.c", but the equvalent wasn't "occam.c". Instead, it would be 12 files with names like ~24nkj24.jd8 and the like, which the Occam editor would link into the environment.
One day, we went to run a video test, and discovered that there was less than 2kb free on the 20MB drive. So, one of my teammates cleaned up enough space on the disk to run the test. A day later, the manager of the other group became hysterical that our group had destroyed six months of their work.
Fortunately, my teammate had done a backup of the machine before wiping it, however, the other team's project directory wasn't on the backups.
Where my and other teams used DEVTEAMS, this group decided to go their own way. The decided to use their group member's initials for the directory name. So James, Uri, Norm, and Kwok put all of their transputer files in the subdirectory... C:\JUNK
Yes, on a shared machine, they set up a directory called JUNK, and filled it with 300 binary files with names like $3j5a1.d7x, and were shocked when people looking to clean out dead files didn't realize that those were critical project files.
Although they weren't so critical that their team ever bothered to back them up, of course.