Rothken criticized the way in which the U.S. shut down Megaupload's domain, abruptly cutting off users from data that may have been legally theirs. He has been negotiating with the government to free up funds from Megaupload's frozen bank accounts, which could then be used to pay Megaupload's hosting provider in order to preserve the data.

The U.S. government rejected a deal he reached with Carpathia Hosting, which holds the data, to obtain the physical servers and pay the hosting company around $1 million after the case is adjudicated, Rothken said.

Rothken said he plans to file a brief with the court in a few days asking for the data to be preserved. Other parties have already filed briefs: the Electronic Frontier Foundation, which supports preserving the data for non-infringing Megaupload users, and the Motion Picture Association of America, which expressed fears that if Megaupload controls the data, pirated content may circulate once again.

Rothken plans to argue that under U.S. law, only Megaupload is entitled to control the data. "We believe under the Electronic Communications Privacy Act that data is Megaupload's to handle for the benefit of consumers," he said.