The Federal Trade Commission said on Thursday that it had obtained a court order barring one company's use of the Windows Messenger system to barrage consumers with pop-up advertising.
Microsoft designed the Messenger Service for system administrators to notify users about the network, but acknowledged that some advertisers have found a way to use the service to send advertising messages and possibly viruses.
It advises consumers not using the system to deactivate it.
The FTC action targeted D Squared, claiming the company "engaged in an unfair practice by interfering with consumers' use of their computers, specifically by causing a stream of multiple, unwanted Windows Messenger Service pop-ups to appear on their computer screens."
"The defendants created the problem that they proposed to solve - for a fee. Their pop-up spam wasted computer users time and caused them needless frustration"
FTC consumer protection chief
Ironically, the messages instructed consumers to visit sites that suggest that the barrage of pop-ups could be stopped by purchasing software at a cost of $25 to 30, the FTC said.
"This is nothing more than a high-tech version of a classic scam," said Howard Beales, the FTC's consumer protection chief.
"The defendants created the problem that they proposed to solve - for a fee. Their pop-up spam wasted computer users time and caused them needless frustration."
The FTC said the company also sold or licensed their pop-up-sending software to other people, allowing them to engage in the same conduct, and sold a database of more than two billion addresses of computer users.