The thread on reddit is hilarious for the lack of sympathy. Basically, it seems to have come down to commanding a deletion of a "directory with space in the name" but without quoting which made the command hunt for the word match ending space which was regrettably, the D:\ component of the name, and the specific deletion commanded the equivalent of UNIX rm -rf

The number of people who said "for safety's sake, never name directories with spaces" is high. They may be right. I tend to think thats more honoured in the breach than the observance, judging by what I see windows users type in re-naming events for "New Folder" (which btw, has a space in its name)

The other observations included making sure your deletion command used a trashbin and didn't have a bypass option so you could recover from this kind of thing.

I tend to think giving a remote party, soft or wet ware control over your command prompt inherently comes with risks.

Friends don't let friends run shar files as superuser.