"IA makes a final argument that, even if its Open Libraries project did not qualify as a fair use, we should restrict the injunction to the Open Libraries project and allow IA to continue CDL for books that IA itself owns. In support of that argument, IA argues that the fourth factor analysis would be more favorable if CDL were limited to IA’s own books. In our view, the fair use analysis would not be substantially different if limited to IA’s CDL of the books it owns, and the fourth factor still would count against fair use. So we decline IA’s invitation to narrow the scope of our holding or of the district court’s injunction."
In other words, even if one purchases a print copy of the book, fair use would not allow them to lend a digital copy of the book to one person at a time. Why the court concludes that that "would not be substantially different" is unclear from just this footnote.