An intrusion detection system for altering the operation of an associated machine when an appropriate intrusion is detected, the system comprising: a first detector to detect the presence of a first distinguishing property and to selectively produce an intrusion signal when the first distinguishing property associated with an object is detected within a danger zone approximate a pinch point of a machine, wherein an area approximate the pinch point of the machine does not exhibit the first distinguishing property; and, a controller, operatively coupled to the intrusion detector and the machine, for controlling the operation of the machine, wherein the controller generates a corrective action signal directed toward the machine when intrusion signals are received from the intrusion detector.