A serial junk-mailer known as the "Spam King" will appear in a Seattle court next month, in a criminal trial being hailed as a major blow in the fight against unsolicited emails.
Soloway was arrested in May and charged with sending out tens of millions of unwanted messages. Many went via hacked "zombie" computers infected with botnet software, prosecutors allege.
Also coming up in March is a civil case against Impulse Media Group, for spamming computer users with pornographic emails.
In the Soloway case, the United States Attorney's Office is seeking more than $770,000 (£390,000) in fines, but the Spam King is also facing fraud and identity theft charges that could result in a prison term.
Soloway has previous form. In 2005 Microsoft was awarded a $7.8 million (£3.9 million) judgement against him, but it has yet to collect a penny, according to Aaron Kornblum, a senior attorney with Microsoft. If US attorneys can get money out of Robert Soloway, it will be a first.
Still, Kornblum is hoping that the use of criminal charges – under the 2003 CAN-SPAM law (Controlling the Assault of Non-Solicited Pornography and Marketing Act) – may serve as a deterrent to other spammers. "There have not been a large number of criminal CAN-SPAM prosecutions," he said. "This is significant."
Microsoft has filed 131 lawsuits against US spammers in the US, most of which have ended up in a settlement or a judgement against the spammer. "We have helped change the economics of spam and we've done that across multiple fronts," Kornblum said. "Spammers now sit in jail."
However, one law professor has said that prosecutors shouldn't necessarily rush into criminal cases. "Spam is principally about speech and we should be very reluctant to criminalise speech-based behaviour," said Eric Goldman, an assistant professor with Santa Clara University School of Law who blogs about technology and marketing.
"There's such an antipathy towards spam that there's almost a sense that anyone who ever engages in spam is… so evil that they should be punished," he said. But if people really thought about the issues, they wouldn't necessarily find spam any more invasive than other forms of advertising, like television commercials or junk postal mail, Goldman said.
If criminal prosecutions like Soloway's are deterring spammers, email users wouldn't know it. Security vendor IronPort said that spam volume on the Internet was up 100 percent in 2007, jumping to 120 billion unwanted messages per day.