"Mandating such proof could thus have the pernicious effect of depriving copyright owners of a practical remedy against massive copyright infringement in many instances," she said.
"It is often very difficult, and in some cases, impossible, to provide such direct proof when confronting modern forms of copyright infringement, whether over P2P networks or otherwise; understandably, copyright infringers typically do not keep records of infringement."
Thomas has already been fined US$220,000 for copy infringement after the judge in the original case instructed the jury to accept the argument that storing songs in a shared folder was evidence enough of piracy. He has since said he may have made a mistake and has asked for more information.
"The specious 'making available' argument threatens to brand people as thieves when the evidence isn't really there," said EFF Senior Intellectual Property Attorney Michael Kwun.
"We're pleased the judge is taking a second look at this critical question."
Thomas’ legal team is claiming that as there is no evidence that anyone actually downloaded the music there is no case to answer. The judge is now deciding whether or not to allow her leave to appeal.
The Thomas case was the first pirtacy action for music file sharing to come to trial and the win was seen as a major vicotry for media companies and one that would make future prosecutions a lot easier.