I do know of a guy who was fired at some company and was left to finish his shift. He wasn't escorted out or monitored and decided to place clear scotch tape over a few dozen optical sensors on the production line after his shift. This was on Friday and it took three weeks to get the production line going again. Every section was registering an obstruction when there wasn't, the computer was replaced two times and you couldn't see the tape on the sensor heads. Eventually someone decided to replace everthing on the control and safety circuits and found the cause later.
