Some copying is covered by fair use. Making a whole copy of a book, especially in a way that might limit the copyright owner's profits, usually doesn't count. I've seen signs in libraries like this one https://www.shopbrodart.com/Library-School-Equipment/Signage... warning about copyright infringement.

Those signs may seem scary, but they're just stating a basic fact that everyone already knows: If you commit copyright infringement, you have committed copyright infringement.

Likewise.