Joseph: “If some music, book or software program is no longer offered for sale, you know that you would not have purchased it if you didn’t copy it, so there’s no issue of hasagas gvul.”
That’s what I always thought, but I was once trying to get a hold of a particular Sefer written by a former teacher of mine. It was no longer in print, so I called the author and asked him if I could photocopy it and he said no. I asked him why not since it’s no longer in print. He responded, “well, maybe I will decide to reprint it one day.” (note: the book had not been printed since the 1970’s, this conversation took place in approximately 2010 when the author a”h, who has since been nifter, was in his 70’s at least).
Even though the author was a tremendous Talmid Chacham, he was not a poseik, so I called a poseik to check if he really did have a right halachically to tell me that I couldn’t copy it. The Poseik said that he did have a right to do so.
ps: End of the story: I posted on a local email list asking if anyone had the Sefer. Someone had it and was willing to give it to me for free, which was very nice of her.