I have no problem with creating drm-free copies of ebooks, and absolutely hard no on stealing from libraries.
But I wasn't even saying that. I'm just saying borrow and read the books as per the usual method from libraries. Libraries are awesome and there to be used. I love that public and private funding still gets directed toward the free sharing of media in libraries, reducing (not erasing) the actual need for piracy through their existence, especially for books.
Now what I'm betting is that this is for an overpriced textbook, in which case by all means create copies and sideload them onto an ereader that allows this.