Megaupload founder Kim Dotcom and his co-defendants scored a significant victory on Tuesday when a New Zealand judge ordered the United States government to hand over evidence the defense will need to prepare for an upcoming extradition hearing. He rejected the government's argument that the defendants should make do with the information about its case the government itself chose to introduce in court.

The judge's comments in the 81-page decision, which was provided to Ars Technica by Dotcom attorney Ira Rothken, suggest that he is conscious of Dotcom's trying circumstances and the unusual nature of the case against him. "Actions by and on behalf of the requesting State have deprived Mr. Dotcom and his associates of access to records and information," wrote Judge David Harvey, alluding to the fact that dozens of hard drives were taken from the Dotcom mansion during the January raid and have not been returned. Dotcom, Judge Harvey wrote, "does not have access to information which may assist him in preparation for trial."

Harvey described the case as "more complex than many. The United States is attempting to utilise concepts from the civil copyright context as a basis for the application of criminal copyright liability," he wrote. That "necessitates a consideration of principles such as the dual use of technology and what they be described as significant non-infringing uses."

Rothken said that Judge Harvey's discussion of these issues is a good omen for his client. "It's our view that there's no such thing as a criminal Grokster," he told us, referring to the landmark Supreme Court decision that established copyright liability for inducing copyright infringement by others. In civil cases like Grokster, defendants faced only financial penalties, not jail time. Some legal scholars have expressed skepticism that inducing others to infringe copyrights can be the basis for criminal copyright liability.

An extradition hearing is intended to be much quicker and simpler than a criminal trial, but Judge Harvey must still determine whether the US government has a plausible case for Dotcom's guilt. With a trove of documents furnished by the United States, the Dotcom legal team will be better positioned to argue that it doesn't.

In a separate ruling, Judge Harvey allowed Dotcom to return home to his mansion. He had been barred from the mansion because it was not suitable for the electronic monitoring system he was ordered to wear. He and his family were forced to move to another house nearby. But Judge Harvey has concluded Dotcom is not a flight risk and freed him from electronic monitoring requirements, allowing him to return home.