HERF stands for High Energy Radio Frequency. A HERF gun is like a directional EMP that you can turn on and off. It's a relatively simple thing that could be pretty common if people with garages and soldering irons would just compare notes with each other. What interests ME is a news article that talks about a yakuza who used a HERF gun to cheat at Pachinko.

Here are some of the articles:

In April 1998 police in Japan arrested two yakuza in a peculiar act of theft. They were hacking a pachinko machine with a HERF gun. According to the police, one of the arrested yakuza hid a HERF generator on his waist and an antenna on his left hand. He shot a radio signal toward a pachinko machine in order to interfere with the computer that controls the machine. Using this device, they successfully hit a bull's eye worth 30 thousand yen. The HERF generator was 15 centimeters by 7 centimeters by 3 centimeters. The report neglects to explain how the apprehension of the yakuza came about. Presumably, as in most arrests, the cause was not forensic police investigation, but the word of a snitch. Maybe the perps had been bragging. It's hard not to brag sometimes, especially when you've been really, really slick. It's much easier to be stupid. The consequences are predictable. 

Criminals and pranksters have already started exploiting that weakness. In one of the more harmless applications, a Japanese scam artist rigged up a weak microwave generator inside a suitcase to rip off a pachinko parlor. When he placed the suitcase next to one of the machines (which is something like a cross between a slot machine and a pinball machine) and turned it on, the pachinko machine went haywire and disgorged a pile of coins. The perp managed the trick several times before he was caught.

These two accounts sound pretty different, so I'd like to know exactly how the yakuza from the first article hacked the machine. Did he just point the antenna at the bullseye and count on the current from the HERF to trip the sensor in it? Did he use it to short the computer somewhere? Email me if you find out.