An EMP or Electromagnetic pulse has the ability to "fry" or make electronic devices inoperable. The phenomena was first observed during the detonation of a nuclear device , or a fission bomb (splitting atoms apart to release energy).
An armored car crew consists of three people: driver, guard, and a hopper, whose job is to transfer the valuables between the car and client's facility. The most dangerous part of the transfer is when the hopper enters or exits the vehicle.