revision preference src: Being based on rocket fuel and technology, there were a number of safety issues with these devices. If the operator left off the throttle and then reapplied it, the device would essentially become a bomb. <SEP> tgt: Being based on rocket fuel and technology, there were a number of safety issues with these devices. For instance if the operator left off the throttle and then reapplied it, the device would essentially become a bomb.