Some of the information here is just crazy. I mean, yes, clearly the machine needs to store cached digital versions of documents in order to fax them, email them, or even just offer a "print 20 more of that last thing I did" button. But why in the world would the copier ever need to store 25,000 cached documents???
Easy fix? The drives should be wiped before the machine is resold or returned. (and if there isn't already a way to do that from the menus, there should be.) That's the same standard operating procedure a company should be using for computers. And let's face it, everything is a computer these days.