Annoyed, frustrated and ready to retaliate. That was Paul Brogden, owner of Sure Computers, in Devon, England, when he was engaged in a price war with a rival company.
The rival in question was Complete Computers, which was operated by Colin Baglow, a former friend of Mr Brogden (they had fallen out when Complete Computers had started to undercut Mr Brogden's prices). Mr Brogden claimed that Complete Computers was using pirated software which gave it an unfair advantage.
When Mr Brogden sent out details of his new Web site, he received an e-mail response from Complete Computers with the message "Nice Web site, shame about the prices". This was too much for Mr Brogden. Within a few minutes he had sent an e-mail back to Complete Computers to which he had attached a virus known as Kremlin.
The effect of the Kremlin virus is to fill the target computer's memory with randomly generated information. If the virus is not dealt with promptly it causes the computer to slow down and it effectively becomes unusable.
The e-mail sent by Mr Brogden had the rather inviting message "Our prices are attached, please take a look".
Fortunately for Complete Computers, the person receiving the message was suspicious of its contents and decided to run a virus check before opening the attachment. When the virus check picked up the Kremlin virus, the attachment was left unopened and damage to Complete Computers' systems was prevented.
However, Mr Brogden was less fortunate. His premises were raided by the police and, as a result, his business collapsed and he became unemployed. On top of this, he was found guilty of an offence under Britain's Computer Misuse Act and sentenced to 175 hours of community service and his computer equipment confiscated.
The judge made it clear that had the consequences of Mr Brogden's e-mail virus been more serious he would have been imprisoned.
Mr Brogden is not the first person in Britain to be convicted under the Computer Misuse Act. In 1995, Christopher Pile (aka The Black Baron) was sentenced to 18 months' imprisonment (coincidently by the same judge) as a result of writing and distributing a virus-writing tool kit, known as Smeg.
In the United States, the creator of the infamous Melissa virus was convicted after pleading guilty to the federal offence of computer fraud and misuse.
The position regarding criminal liability in Hong Kong for distributing viruses is governed by the Crimes Ordinance. This ordinance was amended back in 1993 to make it an offence for a person to send a virus with the intent of affecting the data or programs on another's computer. It also is an offence to store a virus with the intent to use it in the future.
Employers should also be aware that they can be liable for the criminal acts of employees if they authorise the act or turn a blind eye to what is going on. Accordingly, employers should take immediate steps if they become suspicious that an employee has created or is storing a virus without appropriate authority.
Any such steps should be taken in addition to standard procedures for the handling of incoming e-mails, such as scanning the e-mails for detectable viruses and referring suspicious e-mails to the IT department for checking before they are opened.
Such basic safeguards can help minimise a company's losses and legal liabilities in the event that its IT systems are affected by an incoming virus or it passes on a virus to a third party.

First published in South China Morning Post in May 2001.