How is Anna's Archive getting around the copyright violations of hosting all these books for access to all? I suspect it won't be long before they get sued and are forced to shut down. I spent some time reading the web site, and it doesn't look to be a well thought out project. Even the way it is organized leaved much to be desired. There's much more to library science and the organization of a vast collection of books than meets the eye.
Unlike archive.org which is a real business, Anna's Archive is basically piracy. You could try to sue them but you'd have to find them first. This IMO makes them more resilient against that sort of thing, and also means they can actually do their job.
Anna's Archive merely indexes copyrighted content. It doesn't host.
They evade judicial enforcement and try to stay anonymous. They've certainly already been sued (and lost by not even turning up). https://en.wikipedia.org/wiki/Anna%27s_Archive#March_2026_pu... (Contrast to Sci-Hub trying to defend themselves in court, in India, and that leading to no new articles since several years ago.)