Once the only evidence is in possession of the prosecutor, they are legally required to provide it all to you. On the other hand, things can often get 'lost,' 'misplaced,' or 'forgotten' that are crucial to the defense's case. I assume that MegaUpload wants access to the servers to extract the evidence themselves.
I gather that what makes this problematic is the expense of recovering evidence from the servers, as the hosting company is owed millions of dollars for them. MU does not have millions of dollars anymore.
