In high school, circa '97, I was working in a computer lab. As I entered the room, I was rapidly admonished "<i>don't touch the table!</i>" So naturally, I reached out, tenderly as possible, brushed the table with my fingertip. Sure enough, the computer immediately reboots. He cusses a blue streak, as he's been trying to install Windows but folks kept touching the table! I regret not talking him through the issue, because obviously nobody would use such a flaky machine... but I'd (quite reasonbly) lost his goodwill in my initial mischeviousness. To this day I don't know how the machine was so sensitive to, presumably, a miniscule change in capacitance. There's a possibly that it wasn't grounded and I was carrying a nontrivial electrostatic charge, but the table surface was insulating!