Seriously though...
My worst day was probably back in my old IBM mainframe programming days. I was writing some code to try to pass data from a PC to a mainframe and then back again. At the time this was leading edge stuff - hard to believe I know.

I had written 2 programs, program A and program B. A called B. However, program B was falling over and program A wasn't handling the news very well and insisted on repeatedly calling program B (which continued to fall over) until some kind of mainframe spool file filled up and the whole frigging mainframe fell over.

End result - the whole company - 1000s of people - ground to a halt for the afternoon, unable to do any work at all. The techie boys were totally mystified as to how I had managed to bring down the entire mainframe through some mere COBOL/CICS commands, and IBM were called in to investigate. Apparently my programs were taken away for further study.

Miraculously I didn't get too much of a bollocking for it, but I was shitting myself all afternoon, awaiting the boss' hand on my shoulder.
(Reverend Fister "a disciplined fuckwit", Tue 21 Sep 2010, 15:14, 1 reply, 15 years ago)

First DOS attack
ever? And a home goal to boot.
( Kroney, Tue 21 Sep 2010, 15:32, Reply)

Showed my age there for a minute...
I interpreted DOS as Disk Operating System, the fore-runner of Windows - rather than Denial Of Service.

Shit, I'm old.
(Reverend Fister "a disciplined fuckwit", Tue 21 Sep 2010, 16:07, Reply)