I have worked in electronics, both communications and security systems for decades. The industry is full of magic, satellites that can read license plates, not just from space but inside parking garages and tell you the sex of the baby you may not know you are carrying yet. Industry people, us and terrorists, all know what exists and where it is. You only have to track the contracts and installations. It is all public information, public information the public knows nothing of. Terrorists know, believe that.