Public prosecutor Roelof de Graaf also asked the court not to return de Wit's computer, and a CD-ROM containing computer viruses.
De Wit was charged with spreading data through a computer network, with the intent to cause damage. The maximum penalty for the offense is four years' jail and a fine of up to 100,000 Dutch guilders (U.S. $41,130).
It is the first time in Dutch history that a writer of a computer virus is being tried. De Wit had written the worm with a worm-making toolkit, then posted it on an Internet newsgroup, from where it spread across the world.
De Wit's lawyer claimed that there was "no convincing evidence" that his client had caused any damage or disruption of service and asked for his client be released, and his belongings returned.
Actually, the FBI had sent a fax to the prosecutor saying it had identified 55 victims of the Kournikova worm, and damages of US$166,827, but the prosecutor said the claim was not specific enough.
On his part, de Wit admitted being fascinated with computer viruses. "I was fascinated. Such a small program that can create that much damage," IDG news service reported him as saying. He had collected and catalogued thousands of viruses and Trojan horses.
However, he claimed ignorance of the effect of his worm, which purported to be an e-mail with an attached picture of tennis star Anna Kournikova. Once the attachment was opened, the worm sent itself to addresses in the user's Outlook and set the computer up to visit the Web site of Dutch computer store chain Dynabyte, de Wit's employer.
"I just clicked away," he said. "I did this without thinking and without overseeing the consequences and without the intend to cause damage to anyone."