You have probably never heard of him – but you have almost definitely had a message from him land in your inbox.

Robert Soloway, known as the “Spam King” for the billions of unsolicited junk emails he has sent worldwide since he started his illicit empire, has been arrested in America. His internet reach was so extensive that police say most computer users will have received at least one of his messages in the past four years.

Mr Soloway, 27, is accused of hijacking thousands of computers, infecting them with malicious viruses, and then using them to flood inboxes with torrents of spam. His fraudulent empire funded a life of luxury including a 17th-floor water-front luxury apartment in Seattle and a top-of-the-range Mercedes Benz.

“He is one of the bad ones,” John Reid, an investigator with the European antispam organisation Spamhaus, said. “He’s one of the longest running and uses criminal methods all the time. Anyone on the web for a while would have received one of Soloway’s spams.” Experts say that about 70 billion spam messages are sent every day worldwide.

Mr Soloway faces decades in prison if found guilty of 35 charges of fraud, identity theft, money laundering and email fraud. Despite four of his bank accounts being seized by authorities, police believe he has dozens more. They say he opened and closed accounts faster than creditors could track them.

Prosecutors allege that Mr Soloway preyed on computer-gullible business owners who thought they were hiring a legitimate company to help to increase traffic to their website. He then used their sites to send waves of spam in their names. When they complained, he threatened to charge them extra fees and report them to collection agencies.

Mr Soloway is also accused of hijacking computers to send millions of unsolicited emails, by infecting them with viruses that surreptitiously commandeer them to send the emails.

The computers are known as “zombies” because their owners often do not realise that their hardware is being used to send illegal spam. Many of his bulk emailings, therefore, had as their sending addresses innocent internet users and their email addresses. Kathryn Wilma, the federal prosecutor handling his case, says Mr Soloway used about 2,000 “zombie” computers at a time.

Mr Soloway is accused of covering his online tracks by using at least 50 different website names, registering some through Chinese servers.

Spammers make money in a variety of ways. One of the simplest is to have a business model that lets them make money as long as people visit their website, because the spammer gets advertising revenue from the banner ads attached to the page. Although the vast majority of recipients delete spam before reading it, just a small response rate can generate huge revenues.

In the US, bulk emailing is legal, but only if the sender is honest about where the email is coming from – and if the recipient can opt out of the mailing without being ensnared.

Mr Soloway has been sought by authorities for several years, and was an infamous figure in cyberspace. One website, solo-waysucks.net, had a variety of personal information about him, including his driving offences, and a link on how to call his mother.

“Punk”, “worm”, “piece of s***’, and “bloody gutless cowards” were among some of the website’s tributes. Yesterday, one wrote “Busted!”, another “Fantastic news!”.

In 2005, Microsoft won a $7 million judgment against Mr Soloway, after it sued it him over spam sent through Microsoft’s MSN and Hotmail services. Later that year an internet service provider in Oklahoma won a $10 million judgment against him. But neither has been able to collect a cent. Computer experts said that even with Mr Soloway’s arrest, the world’s junk email boxes would continue to fill rapidly. Spamhaus says that operators in Russia and Ukraine overtook Mr Soloway on their list of the world’s ten worst spammers last year.

“In the short term, the effect it’s going to have is more symbolic more than anything else,” said John Levine, co-author of Fighting Spam for Dummies. “Soloway is a large spammer, but hardly the only one.”

You have mail
2.4m: the number of spam emails MSN says it blocks daily

$100bn: cost of computer repairs and lost productivity this year
71%: of email users filter spam

51%: of internet users say they have lost trust in email because of spam

$5.5m: the amount MySpace won from TheGlobe.com in spam compensation in February

Sources: Pew Research Center; ePrivacy Group; insideSpam.com; Ferris Research

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