I've dealt with e-discovery sets. No one really has answers to what to do when you have a litigation hold on data. Legislation commonly requires "retention of anything related to X case", but how do you know what's relevant and what isn't? When you are a third party the ambiguity increases. So you end up with an everything and kitchen sink data dump. Even with everything the data is commonly useless without context. You have files without access logs and logs referrencing local namespaces etc...

With a 25 petabyte discovery, I'm not surprised that everyone's scratching their heads on what to do next. This isn't just an MPAA/Megaupload problem. Even a smaller dataset like a 10-20TB discovery has numerous problems. Hosting/indexing/classifying/reviewing millions of documents is an open issue for the legal field. What do you do when there are multiple parties who all need to see "everything"? If everyone does their own thing how do you reference materials in a consistent manner across the interested parties? If you all agree to host the data in a neutral place who pays for it? What if the technology of that host benefits one party at the expense of another?

For years the legal field has had a "print it all out and have a team of paralegals go over it" viewpoint. Clients don't pay for computers, but they do pay for paralegal hours. Only recently has that become untenable. Discovery sizes are growing exponentially per year. It's common to have a new discovery set come in larger that every previous set combined, and the legal industry doesn't really know what to do about it.