As technology advances newer methods and gadgets for surveillance are manufactured using the latest state of the art know-how and the equipment gets virtually invisible as well.
Whether it is the good guys or the bad guys, newer gadgets for surveillance have come into play, displacing the older ones. The devices are more sophisticated, their range is greater and their visibility and detect-ability is also less. While old fashioned physical surveillance will always be around, these new gadgets make surveillance activities easier.
Audio Gadgets