I would think that compared to downloading the same or similar material from Napster (or one of its successors), recording a few songs from a CD is an extremely trivial form of "theft." It is reasonable to permit recording of some limited amount of material for your own use. The question is where to draw the line. And where line drawing is the issue, a good rule of thumb is to draw the line where the law says it should be drawn. So there must be a copyright lawyer out there somewhere; what does the law say is "fair use" of a song?