The techniques of intrusion and the countermeasures required are as sophisticated for industrial espionage as for other types of espionage. Electronic surveillance is conducted through clandestine transmitters, telephone wiretaps through analog or digital systems, microphones and wire, and intercoms and related devices. Countermeasures should include physical security measures, technical measures, and an awareness program. Technical security should be accomplished through electronic sweeps conducted either by the company's staff or by an outside security firm. The company's security should use great care in selecting an outside firm, focusing on background checks of staff, the type of equipment to be used, the methods to be used, and the contractor's background and experience. 3 references. (Author abstract modified)