Exit Procedures and the "V'Ger Rule"
I've ended up writing "Exit Procedures" for previous employers just because they didn't consider this.. and invariably used myself as the first example.
No matter what the reason for my departure **, I like to make sure that my now ex-employer can't claim I left back-doors into systems. and that everything will continue to run without the presence of my user account. If I'm gone, I'm TOTALLY gone, end of story.
(** I've never been sacked from an IT gig, only from a summer job as a waiter. One of my "mates" phoned up the restaurant and posed as an angry customer who claimed that I'd told him to f**k off)
As I said on the Internet Storm Center a few years back...
When I design or build a system, I make absolutely sure that it's designed to what I call the "V'Ger Rule". If you've seen "Star Trek: The Motion Picture", you'll understand.
Put simply, the "V'Ger Rule" states:
"A System must continue to operate in a correct and safe manner in the absence of its Creator".
Or, put another way:
1. No blowing up any spaceships ;
2. No joyriding in Carbon Units ;
3. Fat, balding starship captains are to be shot on sight, especially ones that follow the "If you can't eat it, drink it, steal it, spend it or have sex with it, blow it up" mantra.