From the Josef K Guide to Tech terminology:

EMP gun: n. Always suspected but never seen, the EMP -- electromagnetic pulse -- weapon is the chupacabra of cyberspace. Accordingly, it is said to be responsible for much nettlesome corporate computer and bank failure, almost always in countries where such things cannot be verified.

Usage: Pelham was amused when the overly gullible newspaper reporter published his frank lies about Russian computer programmers knocking over international banks with emp guns made from stolen Radio Shack equipment.

------------

One of the most persistent fairy tales propagated in information warfare circles is the urban legend of the electromagnetic pulse gun. When it shows up in the mainstream media, courtesy of Reuters or the Associated Press, it looks something like this:

"Dateline BRUSSELS -- Criminals can use the Internet to create powerful electromagnetic weapons that threaten society with chaos and destruction, a Latverian military officer warned Friday.

"Underground sites on the Internet contain instructions on how to put together dangerous weapons that use electromagnetic or high-energy pulses that cripple computer systems, telephone systems and alarms, according to Victor von Doom, chief engineer at the Defense Materials division of the Latverian armed forces' electronic systems division.

"High-tech goods found everywhere in the world can be used to create powerful weapons using recipes found on the Internet," said von Doom at a meeting of the International Association Of Quack Computer Consultants in Europe.

"The problem is spreading from Russia, von Doom said."

Pretty scary. But sensationalistic garbage that was actually published by one of the wire news services. Crypt News only changed the names of the parties involved.

Crypt News took the time to talk to some scientists at Sandia National Laboratory in Albuquerque. Neal Singer pronounced it an interesting urban legend. Sandia, of course, is one of the national laboratories responsible for weaponization of the U.S. nuclear arsenal. The lab has also done extensive research into shielding against and generation of electromagnetic pulse effects.

Awareness of electromagnetic pulse effects happened in 1962 when a 1.4 megaton nuclear weapon was detonated in Test Shot Starfish. The Starfish shot was conducted 400 kilometers high above the mid-Pacific and the electromagnetic pulse from it destroyed satellite equipment and blocked high frequency radio communications across the Pacific for 30 minutes. "Strings of street lights in Oahu went out and hundreds of burglar alarms set off when the pulses overloaded their circuits," wrote William Arkin in "S.I.O.P.: The Strategic U.S. Plan for Nuclear War." A scientist at Lawrence Livermore, Nicholas Christofilos, had predicted this effect earlier in the rear, calculating that high energy particles from a nuclear burst high in the atmosphere would become trapped in the Earth's magnetic field, producing a series of lightning-like pulses.

Since then, the idea of using electromagnetic effects as a death ray, of sorts, produced without a messy 1.4 megaton nuclear explosion, has become increasingly interesting to fans of the weird quack-science of non-lethality and, for some reason, computer security experts and teenage hackers. For example, Crypt Newsletter frequently receives poorly spelled advertisements put together by teenagers advertising schematics for electromagnetic computer death rays for about $5.00 cash U.S. These, along with instructions for turning the telephone handset into an electric chair, software for melting the circuitry in a PC, and recipes for poisoning enemies with arsenicals -- come dirt cheap on pink photocopying paper or cheesy-looking pamphlets sold at "Survival Books" in north Hollywood.

Interestingly, Winn Schwartau did much to embed the myth of the emp weapon in the mainstream imagination with his 1994 book "Information Warfare." In it, Schwartau wrote of secret U.S. missiles used against Iraq in the Gulf War to short circuit communications through bursts of microwaves. It was an interesting mistake based on a more prosaic reality having nothing to do with emp weapons. In the Gulf War, the Navy used a few Tomahawks containing spools of carbon filament. The filament was deployed across Iraq's power lines and stations by the Tomahawks, causing black-outs by short circuit around Baghdad. According to Michael R. Gordon and Bernard Trainor in "The Generals' War," an account of the Gulf conflict, the military had gotten the idea for the special Tomahawks in the mid-80s when one carrying filament went awry over Orange County, California, and caused a local power blackout.

Since Schwartau's book, the tale has been seized upon by hackers rather too eager to sell gullible journalists on the pseudo-reality of imposing feats of technical legerdemain. In one such story, "Hack Attack," published as a cover feature in a 1996 issue of Forbes ASAP magazine, a number of "dangerous ex-hackers" played the game, "Let's lie to the journalist." The emp-weapon-used-against-Iraq myth was deployed:

Forbes writer: Have you ever heard of a device that directs magnetic signals at hard disks and can scramble the data?

Dangerous ex-hackers, in unison: Yes! A HERF [high energy radio frequency] gun.

Dangerous ex-hacker A: This is my nightmare. $300: a rucksack full of car batteries, a microcapacitor and a directional antenna and I could point it at Oracle . . .

Dangerous ex-hacker B: We could cook the fourth floor.

Dangerous ex-hacker A: . . . You could park it in a car and walk away. It's a $300 poor man's nuke . . .

Dangerous ex-hacker A, on a roll: They were talking about giving these guns to border patrol guards so they can zap Mexican cars as they drive across the border and fry their fuel injection . . .

Dangerous ex-hacker A, really piling it on: There are only three or four people who know how to build them, and they're really tight lipped . . . We used these in the Persian Gulf. We cooked the radar installation.

In other parts of the article the "dangerous ex-hackers" discuss the ease of building what purports to be a $300 death ray out of Radio Shack parts and car batteries. In a rare moment of intellectual honesty and self-scrutiny the "dangerous ex-hackers" admit there are a lot of "snake oil salesmen" in the computer security business.

The sticking point of the legend, according to Sandia's Singer and others Crypt News interviewed, is the generation of militarily interesting amounts of electromagnetic pulse. To generate the effects ascribed to the notional weapon requires power fluxes that would kill everyone triggering the device and everyone in the vicinity of the detonation and target. Far easier to use Tim McVeigh's fuel oil-soaked fertilizer truck bomb.

John Pike, director of the Federation of American Scientists' Space Policy Project puckishly commented, "[This] is sorta like Dr. Strangelove saying that a Doomsday Machine 'would not be dificult'! It is easily within the reach of even the smallest . . . nuclear power."

Nevertheless, the myth of electromagnetic pulse weapons remains powerful, gaining lodgment in the damndest places. Indeed, in Crypt Newsletter 42 one article discussed how a U.S. Army course on information warfare in Carlisle, Pennsylvania, was instructing about them in its sub-lecture devoted to weaponry.

Now, Crypt News provides a thumbnail list of the myth's characteristic hearsay.

1. The emp gun is always seen in remote places, as in "Boris Badenov, a computer security consultant, said criminal hooligans had destroyed a bank network in Dvinsk with an emp gun and escaped with 8 millions rubles in blackmail money."

2. The emp gun is always developed by adjunct professors, fringe military reservists, or hackers. For example: "Glip Popple, an adjunct professor of information warfare at the Technical University of Gobble-Wallah in Australia, said he had built a working emp gun for $2,000," or "Uber-Fiend, a hacker for a group calling itself Karn Evil 9, told Reuters correspondents he had built a 12 gigaJoule electromagnetic pulse projector."

3. Emp guns are always secret, protected by classification, as in, "W. E. van Azathoth, a computer scientist genius working for the northern Virginia company Nefari US Electronics, had written a working paper on constructing emp weapons from four bags of sour cream and onion potato chips, a roll of aluminum foil and a positronic hammer -- it was immediately seized and classified by the National Security Agency.

4. Sometimes only unnamed "experts" talk about emp guns, as in: "Experts have revealed to Associated Press reporters that U.S. banks lost $90 billion due to electromagnetic pulse attacks in 1996 -- the assaults untraceable, the perpetrators -- unknown."

5. Illicit emp gun blueprints are on the Internet. Usage: "This reporter was told by a very highly placed Pentagon consultant that plans for emp guns were on the Internet and that teen hooligans and criminal gangsters had obtained them."

Indeed, it must be considered that in a country where a googly-eyed eunuch can persuade a large group of educated adults to poison themselves in preparation for hitching a ride on a flying saucer and a significant portion of the citizenry cannot be convinced that aliens didn't land at Roswell, the emp gun must be a lead pipe cinch to sell.

-----------------

More relevant links: