Thwarting the information thieves: Fear of spying through simple or sophisticated electronics has spawned an industry whose challenge is to block the illegal interception of intelligence

The building was dark, the employees gone for the day. when a team of experts trained in electronic surveillance entered. They went to work quickly. In an office in the heart of the building, one of the experts unscrewed a power-outlet plate and placed a small radio transmitter inside the cavity. Another lifted the plastic casing off the office's telephone; with a screwdriver and needle-nose pliers he altered the circuitry of the telephone so someone tapping the line could listen to conversations in the room as well as on the telephone line. Meanwhile, a third team member was down the hall in the building's telephone room, attaching a small inductive tap to the wire pair leading to the office.