Dish encrypts the files that you place on an external hard drive so that they can only be read from a dish receiver that has the external hard drive option enabled. To my knowledge, this encryption has not been broken.
Hey, Tommy Faust with DISH Network here. Just dropped by the forum and saw this post. Sorry to revive a dead thread, just wanted to add clarification to AZDude39's answer. That is correct that they're encrypted. Our receivers reformat the hard drive when it's plugged in, and when put back onto a computer it re-formats again to be compatible so the recordings can't be transferred.