[ghaff]

In the US, as far as I can tell, there's no such thing as an officially-recognized library--at least at the federal level unless you're talking about the Library of Congress.

The IA is a 501(c)(3) organization but they're not a "library" in that filing (which may not even be a specific option).

Classification (NTEE) Human Service Organizations - Multipurpose (Human Services — Multipurpose and Other)

Nonprofit Tax Code Designation: 501(c)(3) Defined as: Organizations for any of the following purposes: religious, educational, charitable, scientific, literary, testing for public safety, fostering national or international amateur sports competition (as long as it doesn’t provide athletic facilities or equipment), or the prevention of cruelty to children or animals.

But, sure, they look like a library so they're free to call themselves one. But that doesn't actually confer a lot of special privileges.

[nybble41]

17 U.S. Code § 108[1] grants copyright exceptions specifically to "libraries or archives". This is completely separate from their status as a 501(c)(3) non-profit origanization for tax purposes.

[1] https://www.law.cornell.edu/uscode/text/17/108