I was working in the web interface of one of our appliances at work just before lunch. One of my coworkers (with whom I share admin duties of this appliance) set his computer to shut down then left to pick up some food. Suddenly I noticed the appliance was unresponsive! I was getting site not found errors, and I couldn't even SSH into the machine. I look at my coworkers computer and realize it's still running, but the last command he ran was a shutdown in a remote shell...
That's where molly-guard[1] comes in; stops (or at least confirms) shutdown on protected hosts. Named after the Big Red Button Cover of hacker-lore[2].
I've heard of people doing things like having a terminal background colour escape sequence in their login scripts as well, so it's immediately obvious if you're on a production host.
Given the well-established treachery of my finger muscle-memory, I'm much more comfortable with a hard interlock than something that relies on me checking the prompt. Definitely better than nothing though.
