[australis]

There's also the chance of it happening when writing a script

Such as this classic:

https://github.com/MrMEEE/bumblebee-Old-and-abbandoned/commi...

[jzwinck]

Ten years prior to that, Apple had a similar bug in one of its installer scripts on OS X. I have a hard time finding much about it online now, because it happened at a time when OS X and the Internet were a lot less popular than today, but what I recall is that an unexpectedly customized installation directory (say with spaces or one level closer to "/" than the default) would cause the installer to delete a whole lot of things.

[iopq]

I once installed GGClient in C:/Program Files/ instead of any particular folder

so of course, I said "I'll just uninstall it from there and install it in the correct folder" and it proceeded to delete C:/Program Files/

[bentcorner]

There's also this one from Pool of Radiance's 2001 release:

http://www.rpgfan.com/news/2001/1416.html

Uninstall wipes out your Windows directory.

[Paradigma11]

I still have nightmares from this buggy mess. To add insult to injury the shop didn't want to take the game back afterwards.