Ron Hudson asked: "Let's pretend someone got a hold of a bootlegged, unlicensed ebook of one of your books (or diagram collections). Assuming the item is available for sale (but maybe not in this format), would it be acceptable to pay the author directly for the copy, if that venue of communication were available?"
I think you'd find that pirating the book, or abbetting pirating, would constitute a problem. Most boks state on the reverse of the title page hat it is illegal to make unauthorized copies. You can make a copy of part of a work for yourself under fair use conditions, but certainly not sell it. If the author were to accept payment, that might seem fine in terms of copyright, but the publisher would be very unhappy. An author I know did something along these lines, and the result was that his publisher now won't have anything to do with him. So my advice is, buy the book, even if the author seems to get less in the short run, because otherwise they might be cut right off in the long run. Any help? best, Andrew Dewar