Whoo, Ayn Rand! Remember kids, always strip the DRM from your files and back them up on your computer! Now you know and knowing if half the battle.
Does anyone know how Amazon identifies the files on your Kindle? Is there something in the DRM that identifies it for Amazon? Or will they only pull DRMed files? It shouldn't be the metadata because someone could have a book listed at Atlas Shrugged by Ayn Rand and it might just be a document the reader made from online SparkNotes or something.