alt Hacker NewsNiche text. It's not impossible that there was only ever under a thousand of them printed and released into circulation.
A digital copy would exist somewhere, of course. But for us, that only matters if we can buy or download it. And for AI companies, that only matters if they can get a digital copy DRM-free and licensed permissively enough.
This argument doesn't make any sense. All manner of AI companies just ingest whatever random text they can find on the internet to train their data, including copyrighted publications. Why would DRM on a digital copy of a book matter?