"Data crime" is the technological scourge of the 1990s: eight million of the world's 50 million PCs will be infected with computer viruses by 1993; teenage hackers using home computers have already broken into the "secure" computer systems at the Pentagon, NASA, and NATO; computer fraud is estimated to cost US and UK banks and companies two billion pounds every year - and 85% of computer fraud isn't even reported. As our society becomes increasingly dependent on computers, so we become ever more vulnerable to the misuse of technology, whether for fraud, subversion, the theft of sensitive information or sinister military and espionage operations. This book looks at all aspects of data crime worldwide. It investigates the origins of viruses, and tells the stories of the malicious Eastern European virus writers - including "the Dark Avenger", whose destructive programs broke through House of Commons' security in October 1990.