In a complaint filed last week in federal district court in the northern district of California, the social networking site alleges that Wallace and two others ran a scheme that involved creating Facebook accounts, tricking members into providing their passwords, and then impersonating them to send messages to their friends. Wallace and the others allegedly began the enterprise last November.

Facebook argues that the alleged impersonations make the messages especially problematic. "Traditional spam messages are easily identified and ignored," the company wrote in its complaint. "Defendants unauthorized use of compromised Facebook accounts to send spam makes those messages more difficult to identify as spam, because they appear to be personal messages from friends." The social networking site alleges that these messages hurt the company's reputation and goodwill.

Wallace, one of the Web's most persistent spammers, first came to fame as the "Spam King" in 1997, when he ran the email marketing company Cyber Promotions. In addition, the Federal Trade Commission has targeted him for distributing adware. Earlier this decade, a judge ordered him to pay more than $4 million for installing ad-serving programs on consumers' computers without obtaining their consent.

Last year, a federal court in Los Angeles ordered Wallace and another individual to pay MySpace $230 million for sending members unsolicited messages that appeared to have come from their friends.

But despite Wallace's notoriety, it's not clear that Facebook can prove a CAN-SPAM violation because there are questions about whether the federal anti-spam law applies to messages posted to a social networking site, as opposed to those sent to an email address.

"It's not at all obvious that the wall posts are covered by CAN-SPAM," said Seattle-based Internet law expert Venkat Balasubramani. That statute applies to unsolicited messages sent to email addresses. While MySpace persuaded federal courts in Los Angeles to rule that in-network messages were covered by CAN-SPAM, the San Jose judge deciding the Facebook case might rule differently.

Facebook also alleged that Wallace and the others violated the Computer Fraud and Abuse Act by disregarding the site's terms of service, and that they violated the California Anti-Phishing Act. The site is asking for an injunction ordering Wallace and the others to stop sending messages to Facebook users and for monetary damages.

Facebook previously won a $873 million judgment against spammer Adam Guerbuez and his company, Atlantis Blue Capital, but Guerbuez did not appear in court to contest the allegations.

Even when companies win large spam awards, they might not be able to collect them, often because defendants either can't be found or don't have enough money to pay. But Facebook said in a statement that just bringing the case serves a purpose. "Whatever the outcome, we think this kind of persistent legal pressure will act as a deterrent against those attempting to trick and annoy our users," the company said.

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