At $DAYJOB, I was evaluating a data collection software and needed some files for it to read. I had some random text files top-level in my home-directory, so I figured, I would just tell it to read from ~.
I expected that it might read directories recursively by default, but I could just stop it, if it does that.
What I didn’t expect, is that yes, it does read recursively, but also that by default, it deletes the files it has read. It had eaten a good chunk of my home-directory when I realized.
Now you might think, it doesn’t just delete the files, it transfers them to a different place, so surely, the data still exists. And you’d be right.
However, while it reads from directories recursively, it doesn’t retain the directory structure. So, the contents of my home-directory were all still there, just completely flattened in one big folder.