The Atlantic publishes a search tool with the books that have been used to train the machines.

The database includes over 183,000 books.

“These authors spent years thinking, researching, imagining, and writing, and had no idea that their books were being used to train machines that could one day replace them… It may be beyond the scope of copyright law to address the harms being done to authors by generative AI, and the point remains that AI-training practices are secretive and fundamentally nonconsensual.”

https://www.theatlantic.com/technology/archive/2023/09/books3-database-generative-ai-training-copyright-infringement/675363/