When I was a newb contractor about 15 years ago, I wrote a Perl script that had, as a step, to delete all of the files in a current working directory. When I ran the script the first time (as root), I noticed that the operation was taking quite a bit longer than I expected.

Later, I noticed that poor Charlie was frantically trying to locate the backup for that server. Apparently cwd was somehow '/'. I don't know how that could have happened!

Sorry Charlie...