In a network system having a plurality of devices communicating via a network, a method and system for providing an emergency signal is provided. In one embodiment, a device is malfunctioning if the device continuously transmits data to the network without proper authorization. Another properly functioning...http://www.google.com.tw/patents/US20030018922?utm_source=gb-gplus-share專利 US20030018922 - Method and system for providing emergency shutdown of a malfunctioning device
