[Suicide Junkie]

10) 'Chassis Intrusion connector' - A rather vague and worrying name..."

Some cases have a little circuit that will send a signal to the motherboard if the case is opened, presumably so the system can send you an email alert if someone opens your case while the system is on... Not really useful, but paranoia sells.


I've seen that in action.
If you open the case, it beeps at you with a message on powerup until you clear it too. It would have to be battery powered.