A man who hacked into the accounts of the dating website, loveandfriends.com, and spread computer viruses has avoided imprisonment after a sentence hearing on Tuesday.

Matthew Byrne, 38, from Kirkby-in-Ashfield, Nottinghamshire, was given an eight month sentence, suspended for two years, after pleading guilty to computer hacking offences at an earlier hearing in September.

He was also sentenced to a two year supervision order, for unauthorised modification of a computer contrary to section three of the Computer Misuse Act 1990, at Southwark Crown Court in London.

Officers at the Computer Crime Unit at Scotland Yard charged the fraudster in May following a year long investigation.

According to the Metropolitan police Byrne guessed weak passwords to hack into users of the London based dating agency's accounts in August 2004. He then defaced the profiles and threatened to delete the dating firm's database if they refused to give him payments.

After tracing Byrne to an address in Sheffield, officers discovered evidence that he was responsible for writing the Mirsa-A and Mirsa-B viruses, which posed as emails from the Fathers 4 Justice campaign group.

Graham Cluley, senior technology consultant at Sophos, commented: "The Computer Crime Unit at Scotland Yard should be congratulated for bringing another hacker to justice, but one must question whether the legal system is dealing with virus writers in a consistent fashion.

"In 2003, 21-year-old Welsh virus writer Simon Vallor received a two year jail sentence from the same judge, and more recently the British Government has approved the extradition to the USA of alleged NASA hacker Gary McKinnon.

"There's a danger that conflicting messages are being sent to the hacking community by allowing Byrne to escape jail time."