WHILE APPLYING BRAKE & SHIFTING TO REVERSE, CAR ACCELERATED IN REVERSE AT HIGH SPEED WITH NO THROTTLE ENGAGED. BRAKE WAS PRESSED THE WHOLE TIME AND PUMPED TO STOP VEHICLE, THERE WAS NO BRAKING. A POLE WAS IMPACTED CRUSHING VEHICLE. NO WARNINGS OF THIS ISSUE. THIS HAS LEFT THE FAMILY IN FEAR OF EVER DRIVING A JEEP. THIS WAS A JEEP LIBERTY 2006 WITH LESS THAN 70K MILES. WELL KEPT MAINTAINED VEHICLE.