'Herds' of wary cars could keep an eye out for thieves

Car alarms are taking a change of direction, in the shape of safety in numbers, the NewScientist reports. Multiple hidden sensors are placed in vehicles that act as a watchdog to other cars. When the driver leaves the car, the signals are switched on and other cars are alerted via these signals. If the car goes out of range - i.e. it moves - before the driver returns and 'unlocks' the signals then the nearest car sends an automated alert to a centralised system…