A hacker who hijacked hundreds of PCs to create a botnet has been sentenced to 41 months in jail by a US court. Robert Matthew Bentley of Panama City, Florida also faces $65,000 (just over B2,000,000) in fines and will be under supervision for three years on his release. A botnet is a collection of computers under the remote control of a malicious hacker who then uses them for their own purposes. Most spam or junk e-mail is thought to be routed through hijacked PCs.

The hijacked PCs were used to attack other computers and install programs that plagued users with pop-up adverts.

He was caught following an investigation by the Metropolitan Police's Computer Crime Unit (CCU). Hack attack

The investigation began in December 2006 after marketing firm Newell Rubbermaid notified the CCU about an intrusion on its network.
The trail led the investigators to Florida where Mr Bentley was using computers to co-ordinate attacks.

He and his accomplices drove so much data through the hijacked Rubbermaid machines that it almost brought the firm's network to a halt. The damage cost $150,000 (B5,000,000) to put right.

Aiding the investigation were the US Secret Service, FBI, security firm Sophos and other law enforcement agencies.

The hacking team was paid for every machine on which they successfully installed the ad-serving software and, according to US Department of Justice, made thousands of dollars out of their series of attacks.

"These computer criminals have no qualms about infecting computers around the world and causing thousands of pounds of damages," said Bob Burls, from the Metropolitan Police Computer Crime Unit in a statement.

"In their greed, they cause devastating damage to both private and company computers."

Following on from this court case, life without the internet is unimaginable for the millions who use it every day. But one of the world's leading academics on the impact of the net warns we could be facing its destruction. It is 20 years since the first incident of hacking. A student at Cornell University launched a worm that within a day had compromised an estimated 5-10% of all internet-connected machines.

That was in 1988, when there were about 60,000 computers connected to the internet.
The 23-year-old student responsible, Robert Tappan Morris, was given a $10,050 fine, three years probation and 400 hours of community service. He is now a professor at MIT and worth millions of dollars after selling a dot com company to Yahoo. But he was the first of a generation of hackers, who by and large subscribed to the idea "do no harm".

Hacking has changed and the public have not adjusted their PC's security to the threat of viruses, spam, worms, phishing and fraud. It is estimated that the number of PCs involved in botnets (networks of infected machines open to instruction by the creator of the code which infected them) is 100-150m, or a quarter of all PCs on the internet, as of early 2007. Bad code used to be like graffiti,� it is now like the drug trade, argues Jonathan Zittrain, professor of internet governance at the Oxford Internet Institute. He says the internet is fragile - and on the path to destruction.

Prof Zittrain, who is also the author of The Future Of The Internet And How To Stop It, says that from 1998, hacking exploded. It is now all about making money.

"We have absolutely seen the drug trade equivalent: the business model for infecting these machines either to steal their bandwidth and their processor power and sell it to the highest bidder to direct those machines to all try to load a single website at once to bring down that website, or we've started to see both the use of those zombie machines to send spam and to harvest personal details off those machines."

Losses from online credit card fraud alone totalled �212m in 2007, up