The adult Web site "Married But Lonely" may be getting lonelier. The Federal Trade Commission (FTC) has asked a U.S. District court judge to block an allegedly illegal spam operation that uses deceptively bland subject lines, false return addresses, and empty "reply-to" links to drive business to the site.

The FTC has asked the court to order a halt to the deceptive spam, pending trial. It will seek a permanent injunction at trial.

According to the FTC complaint, Brian Westby sent spam with subject lines that would disguise the contents of the e-mail, including subject lines that read "Did you hear the news?" and "New movie info." When consumers opened the messages, they were immediately subjected to sexually explicit solicitations to visit Westby's adult Web sites.

The FTC says because of the deceptive subject lines, consumers had no reason to expect to see such material. The complaint alleges consumers "may" have opened the e-mails in their offices, in violation of company policies, and, in other cases, children may have been exposed to inappropriate adult-oriented material.

Westby's spam provides a hyperlink for consumers who wish to "unsubscribe" to the e-mail, but, according to the FTC, when consumers used the hyperlink in an attempt to get off the mailing list, they received an error message and they were unable to unsubscribe.

The FTC also alleges that the defendant used false "reply to" information in the e-mail, making it appear that an innocent third party was the sender, a practice known as spoofing. As a result, thousands of undeliverable e-mails flooded back to the computer systems of these third parties, deluging their computer systems with an influx of spam that couldn't be delivered to the addressee.

In addition, according to the FTC, it unfairly portrayed these innocent bystanders as duplicitous spammers, often resulting in their receiving hundreds of angry e-mails from those that had been spammed.

In papers filed with the court, the agency says the deceptive practices violate the FTC Act. The complaint says the St. Louis-based Westby and his businesses have and will continue to injure consumers, and that the defendant has been unjustly enriched as the result of his illegal scheme. The agency has asked the court to halt the scheme.