Book and journal publishers file joint amicus brief backing plaintiffs in OpenAI copyright case, citing $5.2B AI licensing market

On 29 October 2026, the Association of American Publishers (AAP), the International Association of Scientific, Technical & Medical Publishers (STM), the Independent Book Publishers Association (IBPA) and Copyright Clearance Center (CCC) jointly filed an amicus brief in support of the author, publisher and news publisher plaintiffs in In Re: OpenAI, Inc., Copyright Infringement Litigation, pending before the United States District Court for the Southern District of New York. The brief asks the court to grant the plaintiffs' summary judgment motion on the merits and deny the defendants'.

The filers' argument, in their own words: fair use 'is intended to adapt — not yield — to changes in technology'; using copyrighted works to train generative AI models does not warrant special treatment; and a market for licensing works for AI already exists and is expanding. They put the AI training-licensing market for all content types at $5.2 billion in 2025, with text the largest share, projected to reach $55.8 billion by 2035.

The brief also cites substitutive outputs as market harm, including the claim that ChatGPT generated sequels substituting for George R. R. Martin's unreleased work, and quotes an OpenAI researcher warning of a 'doom loop' for the web if value is not distributed down the supply chain.

What this does not establish: the court has not ruled on the summary judgment motions, and the brief's characterisations of OpenAI's and Microsoft's conduct are the filers' advocacy, not findings. This is a distinct joint filing by four publisher organisations, separate from the other amicus briefs filed in the same consolidated case.