A Question For Real Airline Pilots

I have a question that can only possibly be answered by real airline pilots
and pilots of the heavy oil-burners at that. Even they may not know - or
want to tell the answer.

I have heard that most if not all of the heavies now flying have special
equipment in them to thwart hijacking. The equipment that I am referring to
is not just an autopilot which is standard but additional mechanical devices
to completely remove control from the cockpit making it possible to take
control away from the flight officers and giving that control to an outside
pilot which could be in a following aircraft or at an airport or anywhere.

Hope a real airline pilot will comment on this question.