US Patent 7091821 Vehicle anti-theft system and method

An anti-theft system comprises a digital code in a key ring. The code is transmitted to a client box installed in a car. The box analyses the code and, in the case of theft, transmits a distress signal to a surveillance station. The surveillance station is equipped with a receiver and a display to display information concerning the stolen vehicle. A person at the surveillance station can stop the stolen vehicle or can use a switch on the surveillance station unit that sends a signal to a receiver in the client box and thus turns off the fuel pump of the car.