The message about the Bear vs. Tank incident reminded me of something that happened a few years back. I don't remember the name or call-letters/numbers of the machine in question, but there was an anti-aircraft gun that the government stopped production on after spending just over a billion dollars on it. It was designed to shoot down helicopters, and hence was programmed to target rotating blades. During a test of the tageting system, it ignored all of its intended targets, and zeroed in on a nearby bathroom exhaust fan. While the technicians attempted to abort the firing sequence, that wing of the building was quickly evacuated.
(From the "Rest" of RHF)