The rule that allows libraries to work is first-sale doctrine: once you bought a physical book you may re-sell or lend it without permission from copyright owner [1].
However you cannot do this with digital books because DRM doesn't allow that. So IA invented scanning physical books (that are legally bought and not circulated after this) as a countermeasure to allow lending digital books the same way as physical.
So do you side with the publishers who believe that "first-sale doctrine" should not apply to digital books?
Here is a quote from Article 109:
> Notwithstanding the provisions of section 106(3), the owner of a particular copy or phonorecord lawfully made under this title ... is entitled, without the authority of the copyright owner, to sell or otherwise dispose of the possession of that copy or phonorecord.
> (c) Notwithstanding the provisions of section 106(5), the owner of a particular copy lawfully made under this title ... is entitled, without the authority of the copyright owner, to display that copy publicly, either directly or by the projection of no more than one image at a time, to viewers present at the place where the copy is located.
This allows library to "dispose" the posession of the book as I understand. So why this should not be applied to digital copies?
I'm not sure what you meant by the quote talking about the right to display the copy - again, a material object - publicly. A used book store or record store is allowed to show the book or record for sale. It's not allowed to, say, play the record for a party - that's the performance right - or make a movie out of the book. It's allowed to display the physical object.
It's not totally clear to me that those are different. For example, if you have a painting or some other flat, static creative work, then public "display" and "performance" are the same. You don't need a positive law to say you can show people a DVD box. Additionally, some works are unique or at least not commodities like a Shrek DVD, in this case how can you let the buyer know what they're buying without letting them watch the DVD or open the book?
There's the questions of whether first sale _should_ apply to digital works in the same way it does to physical works, and whether it _does_ apply to physical works under current law.
I'm teetering at the top of a very tall fence on the _should_ question.
Publishers have always been opposed to digital first sale for a very simple reason: fear that their prices will go to zero. Used physical books prices are pennies on the dollar for new book prices, on the basis of the condition/deterioration issue. The quality/condition issue doesn't exist for digital works. If Amazon could offer "used" digital copies of publisher e-books, the customer would be choosing between identical binaries at 10-1 price ratios _at best_. I really don't see any other way that this goes. Sure, capitalism isn't for the weak, yadda yadda, new models, but how's it going to work. Amazon's Kindle Unlimited is an alternate model, but Amazon already has enormous control over publisher fortunes. "Should the current publishers exist" is a really interesting question. I'm just not sure I want to find out by handing all compensated book publishing to Amazon.
So why am I on the fence? Well, I have paid for 2000+ ebooks. I wouldn't mind being able to transfer them to my children without limitation, or to friends. If there were a resale mechanism no more disruptive than used paper books, I would probably have sold some of them already. It's not that I don't appreciate the value or convenience of resale, but that I consider the side effects.
The second question is, "Does current law support digital first sale?" First off, I am not a lawyer, and I'm not giving legal advice. However, the words of the law are pretty damn clear, to be honest, that it does not. You found section 109, which is correct, but you're relying on the colloquial meaning of the word "copy." You need to look up the words "copy" and "phonorecord" in the definitions, section 101, so that you can see that in this law both words refer to _material objects_ in which a work is fixed.
A paper book is a material object. You can sell the book. The buyer owns the physical book - the stack of paper and binding - and can read it.
A CD or DVD is a material object. You can sell the flashy mirror thing. The buyer owns the flashy mirror thing and can listen to the album or play the movie.
An ebook is just not a material object. In most cases, they are not with a single physical object, but licensed as downloads according to fairly restrictive terms. If you have a physical object with a duly licensed ebook on it, you're probably allowed to sell that physical object (unless it's a Cybertruck, I guess.) However, the license on that download is still going to be what controls. Your Kindle has Kindle software tied to your Amazon account that allows you to read the books you've bought, and I'm really pretty certain you can't sell your Amazon account and all your individual access rights.
Various entrepreneurs have tried to convince courts that some variant of "one-copy-at-a-time" digital first sale tech fits under 109, and courts look for the material object and note that it is not there.
So, anyway, the law is not written so that ingenious digital technology that ensures that a digital copy is only possessed by one person at time can fall under first sale. It's written so that physical objects that contain or embody copyright-protected works can be sold.
Interesting note. Indeed, copy is defined as a material object where the work is "fixed". It looks like it was made intentionally to not let buyers re-sell electronic files.
But there is also a definition of "fixed":
> A work is “fixed” in a tangible medium of expression when its embodiment in a copy or phonorecord, by or under the authority of the author, is sufficiently permanent or stable to permit it to be perceived, reproduced, or otherwise communicated for a period of more than transitory duration. A work consisting of sounds, images, or both, that are being transmitted, is “fixed” for purposes of this title if a fixation of the work is being made simultaneously with its transmission.
And definition of "display":
> To “display” a work means to show a copy of it ...
So does it mean that if we have, let's say, a hard drive with legally obtained ebook (a copy fixed in a tangible medium), and somehow transmit the book (show it to somebody) over the Internet from it without "fixing" (permanently storing) then it doesn't fall under "making a copy" or "display" and is perfectly legal? And maybe we can stream music the same way?
So would it be ok if I stored my ebook on a CD, or printed it? What of I was printing from an online source? I don't think a "material" distinction can be made here between the medium and the message.
However you cannot do this with digital books because DRM doesn't allow that. So IA invented scanning physical books (that are legally bought and not circulated after this) as a countermeasure to allow lending digital books the same way as physical.
So do you side with the publishers who believe that "first-sale doctrine" should not apply to digital books?
Here is a quote from Article 109:
> Notwithstanding the provisions of section 106(3), the owner of a particular copy or phonorecord lawfully made under this title ... is entitled, without the authority of the copyright owner, to sell or otherwise dispose of the possession of that copy or phonorecord.
> (c) Notwithstanding the provisions of section 106(5), the owner of a particular copy lawfully made under this title ... is entitled, without the authority of the copyright owner, to display that copy publicly, either directly or by the projection of no more than one image at a time, to viewers present at the place where the copy is located.
This allows library to "dispose" the posession of the book as I understand. So why this should not be applied to digital copies?
[1] https://www.law.cornell.edu/uscode/text/17/109