A friend of mine worked out how to trip Windows XP's built in shut down program via a network. Hillariously, while it couldn't be stopped it did have a huge countdown of the same kind, which made me laugh..
This happened to me once. Turns out the count down was to my surprise Birthday party. Honestly, computers are getting so smart these days. Why, mine is in the kitchen now, sharpening knives. Here it comes now.