An American ISP allegedly involved in distributing spam and images of child abuse has been thrown off the net.
The US Federal Trade Commission asked for Pricewert LLC's net links to be severed after it had gathered evidence of the firm's 'criminal' connections.
The FTC alleges that Pricewert had created one of the "leading US-based havens for illegal, malicious, and harmful content".
Pricewert denied the allegations and said it would fight them in court.
In an official complaint filed in a San Jose Federal court, the FTC described Pricewert as a "rogue" or "black hat" ISP that acted as a hosting centre for many hi-tech criminals.
The FTC alleges that Pricewert was paid to host "child pornography, botnet command and control servers, spyware, viruses, trojans, phishing-related sites, illegal online pharmacies, investment and other web-based scams".
The evidence against Pricewert was gathered with the help of the National Security Agency's computer crime division, Symantec, the National Center for Missing and Exploited Children, as well as groups such as Spamhaus and the Shadowserver Foundation.
In its statement accompanying its filing, the FTC said its complaint was "not a finding or ruling that the defendant has actually violated the law". That, it said, would be decided by a court. A preliminary hearing will be heard on 15 June.
So far, the FTC has not been able to identify who was behind Pricewert. Although its servers are based in the US, it is registered as a business in Belize and many of its employees are thought to be located in Eastern Europe.
Talking to technology news site Network World, a spokesman for Pricewert said the action was "unfair" and it would take legal action to defend itself.