The "spam king" was sentenced on Tuesday to 47 months in prison, with a ruling that the court hopes sends a message to other online criminals.

Robert Soloway, the man known as the spam king for the massive volume of spam he sent out, pleaded guilty to fraud, spamming and tax evasion after being indicted in May 2007. After an unusually long sentencing hearing lasting two-and-a-half days, Judge Marsha Pechman handed down her sentence in the U.S. District Court for the Western District of Washington in Seattle.

The case has been closely watched because only a few such spam cases have ever been tried. A man named Jeremy Jaynes was sentenced in Virginia earlier this year to nine years in prison for his spam crimes, and Adam Vitale got slightly more than two years for a recent conviction in New York.

The prosecution argued that Soloway should get more prison time than any of the previous spammers, asking for a sentence of seven to nine years. "None of those cases, not one, comes close to this case in terms of the duration of the maliciousness, the harassment techniques, the high level of spamming activity that we have in this case," said assistant U.S. attorney Kathryn Warma.

However, compared with some other notorious spammers, Soloway deserved some leniency, his attorneys said. Soloway didn't damage anyone's computer, he didn't send out malicious code, and he never directed people to pornography, as some spammers have done, his lawyer Richard Troberman said. Jaynes, for example, had millions of AOL e-mail addresses that were stolen from the ISP (Internet service provider), and he was earning as much as US$700,000 a month from his activities, Troberman said. By comparison, the government figured conservatively that Soloway earned more than $700,000 in three years.

But the Soloway case was an opportunity for the courts to dissuade online criminals from continuing their work, Warma said. "A disturbing theme we repeatedly saw from the complainant is, why isn't the law being enforced on the Net? Why isn't CAN-SPAM being enforced?" she said. "This individual has refused to stop his criminal conduct, notwithstanding two separate civil judgments and an injunction by a U.S. federal court judge. I suggest to you the only effective way to stop Soloway is a long prison sentence during which he'll be incapable of continuing this criminal activity." Soloway has previously lost cases brought against him by Microsoft and by an ISP in Oklahoma, yet continued to spam.