Some high-profile computer virus senders who have been caught:
1988 - Robert Tappan Morris released the so-called "Morris Worm" on Nov. 2, 1988, that crippled about 6,000 computer systems -- about a tenth of the Internet at the time, and resulted in about $15 million in damage. Morris, whose father was a computer security expert with the National Security Agency, later said it was just a stunt and that he regretted his actions. He was placed on three years' probation, given 400 hours of community service and fined $10,000. He is now an assistant professor at Massachusetts Institute of Technology.
1991 - Joe Popp of Cleveland, Ohio, mailed about 20,000 copies of software to subscribers of a British computer magazine that included a program that damaged users' computers. He was extradited to England, but then ejected from the country after appearing in court with a box on his head and rollers in his beard. He was later sentenced to six months in jail in Italy on similar charges.
1995 - Christopher Pile, then 26, was sentenced to 18 months in custody in the United Kingdom for writing and sending two computer viruses, "Pathogen" and "Queeg," named after expressions used in the British Sci-Fi comedy "Red Dwarf." He was the first person in the United Kingdom to be convicted of writing and distributing computer viruses.
1998 - The Korean National Police Agency caught a group of university students calling themselves "CVC" who had disseminated information on how to write computer viruses. They were released after authorities concluded their actions were not illegal.
1999 - Chen Ing-hau, then 24, admitted to Taiwanese authorities that he created the "Chernobyl" virus that triggers on April 26, the anniversary of the Soviet Union's nuclear disaster. He wasn't charged initially because police said no one filed a complaint, but a year later, when the virus struck again, he was charged. A police statement said, "He did not expect the virus to cause such a great impact. He regretted his deeds and apologizes."
2000 - Onel de Guzman, then 23, a computer school dropout in the Philippines, was arrested but then released and not prosecuted after authorities realized they had no laws to charge the admitted sender of the "ILOVEYOU" virus, which struck computers around the world causing more than $7 billion in damage. Such laws have since been passed.
2001 -- Jan De Wit, then 20, of the Netherlands, was ordered to perform 150 hours of community service after telling a Dutch court he had no idea of the impact he would have when he created the "Anna Kournikova" virus that snarled e-mail traffic around the world. His collection of about 7,500 viruses was also confiscated. "I don't know what fascinated me. When I think about it now, I should never have started this collection," he told the court.
2002 - David Smith, of Aberdeen, N.J, was sentenced to 20 months in jail and fined $5,000 following plea bargains reached in December 1999 with state and federal prosecutors for creating the "Melissa" virus that snarled e-mail worldwide, causing more than $80 million in damage. Smith, who was 34 when he was sentenced, is in federal prison at Fort Dix, N.J.
2003 - Simon Vallor, 22, of North Wales, was sentenced to two years in jail in January 2003 after pleading guilty in London to writing and distributing three computer viruses, "Gokar," "Redesi" and "Admirer," which infected an estimated 27,000 PCs in 42 countries.