vampire device - Computer Definition
An electronic device that draws current even though the power switch is turned off. A huge majority of electronic equipment today qualifies as vampire devices because they continue to use electricity to power LEDs as well as perform routine processing. For example, many AC to DC power adapters use current even though their target devices are turned off. A cable set-top box may be turned off, but still downloads updated program guides. The only way to kill the power to vampire devices is to unplug them from the wall or plug them into a power strip that can be turned off. See vampire tap.