Skip to content

Analytics cookies

We use Google Analytics and Google Tag Manager to count visits and see which pages are useful. If you accept, Google Analytics may set cookies to recognise your return visits. If you decline, it sets no cookies, but Google still receives a cookieless signal for each page you view. We don’t send Google your name, email address or registration details, and you can change your choice at any time under “Cookie settings” at the bottom of the page. Privacy

PayAuthors white paper: dated pirate-library catalogs as evidence for which books AI companies acquired

Oct 14, 2026 · Gathered automatically from public sources. Not reviewed by a person.

What it is

An October 2026 PayAuthors white paper (text revised Oct. 14, 2026) on how dated pirate-library catalogs and U.S. copyright registrations can support research into which books AI companies acquired for AI development.

The data

  • 22.4M catalog records across overlapping collections (not unique books)
  • 31 dated catalogs and lists: 25 LibGen snapshots (Nov. 2015–Jun. 2025), 4 Z-Library catalogs (incl. two Pirate Library Mirror indexes from 2022), 1 Books3 list (196,608 file names; ISBN list cross-checked against file names), 1 Internet Archive lending-library catalog
  • 8.03M U.S. literary-work registrations covered (1978–2025), 1.52M distinct registrations with at least one candidate catalog match

Key methodological points

A catalog can show that a library listed a particular edition by a particular date, and file identifiers or checksums can help compare a listing with files a company disclosed. It does not establish acquisition: that requires evidence such as a manifest, logs, testimony, or a stipulation. The paper grades evidence (court finding/order vs. company's own account vs. a party's allegation) separately from PayAuthors' own analysis, and notes that its exclusion screen for the Bartz settlement is an estimate, not the administrator's determination.

Case facts the paper draws on

  • Bartz v. Anthropic: court-described downloads of millions of books from LibGen and the Pirate Library Mirror; the final Works List covered 482,460 works under the $1.5B settlement
  • Meta has acknowledged acquiring LibGen and Anna's Archive data in its own filings
  • A discovery order in the OpenAI litigation described an employee's 2018 LibGen download as undisputed
  • Books3 (approx. 196,640 books, released 2020) was included in The Pile training dataset

This is a research guide, not a court document; it reports evidence and methods rather than asserting infringement.

Sources