When the US government shut down file-sharing site Megaupload, it also grabbed the service's US-based servers, located at Carpathia Hosting and other companies. That inspired legal demands from Kyle Goodwin, an Ohio man who makes his living videotaping high school sports events, and wants his files back. But the government shot back with a brief suggesting that Goodwin wasn't exactly "innocent," since he'd also uploaded allegedly pirated music files to his account.

Now Mega wants to intervene in the dispute between the government and Kyle Goodwin—and government lawyers want to keep Megaupload well out of it. In a brief filed yesterday, prosecutors say that while it's fine for someone from Megaupload to be a witness in Goodwin's case, the service absolutely should not be allowed in as a party to the case.

In this new brief, the government accuses Megaupload of trying to use Goodwin's case as a way to battle over its own criminal case—while it actually delays that case from moving forward.

"Megaupload seeks to intervene in this civil dispute, where it lacks standing, to pre-litigate the pending criminal case, where it has not appeared," write government lawyers in their brief. "Here, Megaupload seeks to circumvent numerous procedural rules, as well as basic legal principles, by selectively appearing as a party in one civil proceeding that parallels the criminal prosecution, while seeking to stay all others."

Megaupload chief Kim Dotcom and his lawyers got very interested in Goodwin's case, after it led to documents being unsealed, which they believe aid their case greatly. Getting involved as a party in Goodwin's case would allow Megaupload's lawyers to better attack the warrants that resulted in criminal action.

The US is still trying to get Dotcom extradited from New Zealand—so far without success. Meanwhile, Dotcom has launched a new service called Mega; it was unveiled at a splashy party last month at the Dotcom Mansion.