A computer network engineer explained to Reuters that the domain name pointed to at least two numerical Internet addresses, only one of which was controlled by the government. Users would encounter differing versions of the Web site depending on which address was stored by their "name servers," which match domain names to numerical addresses, the engineer said.

According to the Justice Department, David Rocci, 22, agreed to surrender the site after pleading guilty last December to importing 450 Enigmah Mod Chips from Britain and selling them for between $45 and $60 apiece.

Rocci will face a prison sentence of up to five years and fines up to $500,000 at his sentencing on March 7, the government said.

"David Rocci developed a public Web site that specifically catered to the underground piracy community," said Assistant Attorney General Michael Chertoff. "He attempted to profit by marketing circumvention devices to that community knowing they would be used to play pirated games."