The question in the end is who is responsible for the 'file.' MegaUpload was shutdown because they are being targeted as the responsible party. Most sites like YouTube and others have convinced the necessary parties that they are not responsible.

Once a file is broken down into multiple parts and scattered throughout, can you be held responsible for hosting parts of files? how large does the 'part' have to be to be held responsible? what happens if a file is split into parts and posted on pastebin + github + blogs and a trackers are used to manage and build the files again?

The only thing taking down megaupload will do is create new means to allow sharing to occur.