Authors Guild v. OpenAI: Billions Mass Tort

The Authors Guild and novelists including John Grisham and George R.R. Martin lead the consolidated author class actions accusing OpenAI and Microsoft of training GPT models on their books. An October 2025 ruling that ChatGPT’s detailed plot summaries could infringe is one of the few merits rulings so far to let output-based infringement claims against an AI developer proceed.

LATEST DEVELOPMENT · SEP 5, 2026

In addition to Microsoft’s and OpenAI’s summary judgment motions against the class and news plaintiffs, the Authors Guild and named co-plaintiffs (including George R.R. Martin and John Grisham) filed their own cross-motion for summary judgment on September 5, 2026, arguing OpenAI’s mass reproduction of books was not protected by fair use. Opposition briefs are due in early October 2026 and reply briefs in early November 2026.

Authors Guild, Co-Plaintiffs Seek Summary Judgment in OpenAI Case Authors, OpenAI File for Summary Judgement In New York Infringement Case Authors Guild v. OpenAI Inc., 1:23-cv-08292 — Docket

BACKGROUND

The Authors Guild and seventeen prominent fiction writers, including John Grisham, George R.R. Martin and Jodi Picoult, filed a proposed class action in September 2023, alleging that OpenAI, with Microsoft’s backing, copied their books to train GPT models and that ChatGPT can generate infringing outputs derived from those works. The case was consolidated with the other author and news actions into MDL No. 3143 before Judge Sidney H. Stein in April 2025.

On October 27, 2025, Judge Stein denied OpenAI’s motion to dismiss the class complaint’s output-based infringement claim, holding that a ‘more discerning observer’ could find ChatGPT’s detailed plot summaries substantially similar to the originals, the court worked through a ChatGPT summary of Martin’s A Game of Thrones, while expressly reserving the fair use question. Class discovery is active: OpenAI’s court-ordered production of 20 million de-identified ChatGPT logs, affirmed on January 5, 2026, bears directly on how often outputs reproduce class works, and bellwether selection is expected in late 2026 against the backdrop of Anthropic’s $1.5B Bartz settlement.

TIMELINE

SEP 5, 2026FILING

Authors Guild and co-plaintiffs file cross-motion for summary judgment

The Authors Guild and 13 co-plaintiffs, including Jonathan Franzen and George R.R. Martin, moved for summary judgment against OpenAI and Microsoft, arguing OpenAI’s reproduction of copyrighted books was not justified by fair use and threatens the market for human-authored books.

Authors Guild, Co-Plaintiffs Seek Summary Judgment in OpenAI Case Authors Guild, Co-Plaintiffs Seek Summary Judgment in OpenAI Case
SEP 4, 2026FILING

Summary judgment briefing opens in the MDL. Microsoft moves against the class claims

Microsoft argued that Copilot rarely reproduces books. OpenAI moved on the news plaintiffs’ claims. Briefs are to be publicly re-filed with unchallenged portions unredacted by September 17.

unite.ai chatgptiseatingtheworld.com
FEB 6, 2026PROCEDURAL

Judge Stein finds no privilege waiver over deleted training datasets

Judge Sidney Stein sustained OpenAI’s objection to a magistrate judge’s order finding a waiver of attorney-client privilege connected to OpenAI’s deletion of the Books1 and Books2 training datasets, ruling there was no waiver.

Judge Stein reverses Magistrate Judge's ruling on OpenAI's attorney-client privilege IP Hot Topic: Privilege Preserved
JAN 5, 2026PROCEDURAL

20-million-log production affirmed

Judge Stein upholds discovery central to proving how often ChatGPT outputs reproduce class works.

When Chats Become Evidence — National Law Review
DEC 15, 2025PROCEDURAL

Court rules in part on motion to dismiss Ziff Davis claims within MDL

In the consolidated MDL, the court granted OpenAI’s motion to dismiss some claims but denied it in part as to contributory copyright infringement and removal of copyright management information claims brought by Ziff Davis.

Ziff Davis v OpenAI: Key Copyright Litigation Ruling In re OpenAI, Inc. Copyright Infringement Litigation
OCT 27, 2025PROCEDURAL

Court holds ChatGPT output summaries could infringe

Judge Stein denies OpenAI’s motion to dismiss the authors’ output claims, finding a discerning observer could deem detailed plot summaries substantially similar. Fair use expressly reserved.

OpenAI Loses Bid to Dismiss — IPWatchdog
APR 3, 2025PROCEDURAL

Case consolidated into MDL No. 3143

The JPML centralizes the author and news-publisher suits before Judge Stein in the S.D.N.Y.

JPML Transfer Order
SEP 19, 2023FILING

Authors Guild and 17 novelists sue OpenAI

Proposed class action alleging books were copied to train GPT models. Microsoft was later added as a defendant.

Authors Guild v. OpenAI — AI Lawsuit Tracker

EXPERIMENTAL AI FORECAST

HOW IT IS MADE →

Predicted outcome: Settlement
Model-assigned probability: about 70%
Timeframe: mid-2027 to mid-2028
Model confidence: medium

The most likely end is a negotiated class settlement with OpenAI, and probably a separate, smaller arrangement or dismissal for Microsoft, landing roughly between mid-2027 and mid-2028 with perhaps 70 percent probability. The driver is asymmetric tail risk: Judge Stein has already let output-based infringement claims past dismissal, discovery into 20 million ChatGPT logs is designed to quantify how often outputs track class works, and the deleted Books1 and Books2 datasets keep the pirated-acquisition theory alive, so statutory damages across a certified book class create exposure OpenAI cannot rationally take to a jury while raising capital and preparing for public markets. Anthropic’s $1.5 billion Bartz deal sets the visible floor, and OpenAI’s larger corpus and deeper balance sheet point to a cash component in the $1.5 billion to $5 billion range, likely paired with forward licensing terms and a claims process run through the Authors Guild. The pending cross-motions on fair use are best read as leverage-setting rather than case-ending: a ruling in the first half of 2027 that splits the question, protecting transformative training but not the acquisition of pirated copies or the most similar outputs, is the classic trigger for serious talks before bellwether trials. The leading alternative, at roughly 15 percent, is that Stein grants OpenAI substantial fair use protection on the training claims and guts the class case, leaving only narrow output claims and a modest resolution. A full claimant merits victory through trial and appeal is the least likely path, since neither side has an incentive to hand the Second Circuit the first appellate word on generative AI fair use. Note that the October 2025 and December 2025 rulings are pleading-stage holdings, not findings that infringement occurred.

Output claims survived dismissal; fair use still undecided · Bartz $1.5B settlement sets visible benchmark for exposure · Statutory damages on certified book class create existential tail risk · OpenAI capital raising and IPO ambitions favor clearing litigation · Bellwether trials and log discovery force valuation before trial

Generated automatically by claude-opus-5 on Sep 19, 2026 from this case’s record on this site, and published without editorial review. The probability is the model’s judgment, not a measured frequency; there is no established validation record for these forecasts. Not legal or investment advice. How the forecasts are made →