Notorious spammer Robert Soloway  will get his day in court next month when his criminal trial kicks off in Seattle.

Soloway was arrested in May  and charged with sending out tens of millions of unsolicited messages; so many, in fact, that investigators called him the "Spam King," and his arrest was hailed as a major blow in the fight against spam. Many of Soloway's unsolicited messages were sent out using hacked "zombie" computers infected with botnet software, prosecutors allege.

The United States Attorney's Office is seeking more than $770,000 in fines, but Soloway is also facing fraud and identity theft charges that could result in jail time.

If U.S. attorneys can get money out of Robert Soloway, it will be a first. In 2005 Microsoft was awarded a $7.8 million judgement against the Spam King, but it has yet to collect a penny, according to Aaron Kornblum, a senior attorney with Microsoft.

In a May 2005 discussion group post, Soloway correctly predicted that Microsoft would be unable to collect. "I've been sued for hundreds of millions of dollars and have had my business running for over 10 years without ever paying a dime regardless to the outcome of any lawsuits," he wrote.

With Soloway now facing criminal charges under the 2003 CAN-SPAM (Controlling the Assault of Non-Solicited Pornography and Marketing Act) law, however, his case may serve as a deterrent to other spammers, Kornblum said. "There have not been a large number of criminal CAN-SPAM prosecutions in the U.S.," he said. "This is significant."

To date, Microsoft has filed 131 lawsuits against spammers in the U.S. Most of them have ended up in a settlement or a judgement against the spammer, Kornblum said. Of those cases, 52 remain open or have been dismissed.

"We have helped change the economics of spam and we've done that across multiple fronts," he said. "Spammers now sit in jail."

Soloway isn't the only accused spammer going to trial in Seattle next month. Also coming up in March is a civil case against Impulse Media Group, which is charged by the U.S. Department of Justice with spamming computer users with pornographic e-mails.

Many Internet users may be happy to hear about Soloway's criminal prosecution, but law enforcement shouldn't necessarily rush into these criminal cases, said Eric Goldman, an assistant professor with Santa Clara University School of Law who blogs about technology and marketing. "Spam is principally about speech and we should be very reluctant to criminalize speech-based behavior," he said.

"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 added.

Goldman calls this attitude "spam exceptionalism." If people really thought about the issues, however, they wouldn't necessarily find spam any more invasive than other forms of advertising, like television commercials or junk postal mail, he said.

If criminal prosecutions like Soloway's are deterring spammers, you wouldn't know if from looking at your inbox. Security vendor IronPort said that spam volume on the Internet was up 100 percent in 2007, jumping to 120 billion [b] unwanted messages per day.

"I'm not sure that we should be suppressing them from a legal standpoint," he said. "I’m troubled by many of the prosecutions that I've seen of spammers."

Soloway is set to face a trial by jury on March 24 at the United States District Court for the Western District of Washington.