Thanks to Steve Schear we've put a 1990 article on eavesdropping on RS-232 cable emanations which parallels van Eck's work on VDUs. "The Threat of Information Theft by Reception of Electromagnetic Radiation from RS-232 Cables" By Peter Smulders, Dept of EE, Eindhoven University of Technology Smulders notes that this type of emanation can disclose information, such as passwords, that does not appear on VDUs. And that cable shielding does not always prevent snooping. http://jya.com/rs232.pdf (367 kb)