He now faces ruin and bankruptcy because of his narrowly-foiled attempt to sabotage the British economy by bringing down the nation’s websites and e-mail systems. The former comprehensive school boy is acknowledged by his adversaries as a gifted computer expert who was flawed by greed and arrogance. His open threats display his brazen spite.

When trading standards began to investigate him, he telephoned them and threatened: “Maybe I should put my complaint in the form of petrol and matches.” His final arrest by Cambridgeshire police came after he made a blackmail threat to Nominet UK, the registry that controls all websites and e-mails ending with .uk.

Nominet had issued a notice on the internet warning against bogus invoices being sent by Francis-Macrae to its customers. He telephoned Emily Taylor, the legal and policy director, and ordered her to to remove the warning or he would attack her systems. “I’ve got 200,000 zombie computers,” he told her, “and you have got two hours.”

Police rushed to arrest him before the threat could be carried out. “The risk to internet users in the country would be very great,” Ms Taylor said. “Anybody’s .uk domain names would stop working until the attack ceased. We took that threat hugely seriously.”

Nominet has been awarded £80,000 costs in a civil action against Francis-Macrae and is pursuing him for this money. “He is a very clever guy, much too clever,” Ms Taylor said. “It is a real shame. Now we are going to make him bankrupt.”

One of Francis-Macrae’s principal weapons was spam, the unsolicited mail on the internet. “If you think of spam and the UK together, you come up with Peter Francis-Macrae immediately,” Steve Linford, who runs the spambusting organisation, Spamhaus, said. “He is the worst UK spammer. Anything that would bring him money, he would spam.”

When police first took him in for questioning, Francis-Macrae asked officers for the name of their chief constable. A bogus spam e-mail suddenly appeared around the world threatening to remove £400 from people’s bank accounts to pay for an iPod. The name and telephone number given for the “customer services manager” was the Chief Constable of Cambridgeshire. The police switchboard was jammed with 2,500 angry phone calls in a day.

In the dock, Francis-Macrae appeared to relish his trial, making copious notes and whispering detailed instructions to his counsel. “That’s my Peter,” his mother, Gillian, said. “He’s a confident young man. He didn’t want us in court, distracting him.”

WEB OF DECEIT

Is spam illegal?

No, the Government ignored protests of campaigners and sided with business to make spam legal for marketing purposes. Sending fraudulent messages is a crime

Where did Peter Francis-Macrae begin spamming?

He wrote a spam program at Cambridge Regional College

Where is he based?

He routes his operations from computers in his home town of St Neots, Cambridgeshire, via a server in China, where the web is notoriously hard to police

How could he have brought down Britain’s internet?

He would have used his “zombie” computers as an army to bombard and crash computer systems

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