Wikimedia Foundation seeks to file amicus brief in OpenAI copyright case
The Wikimedia Foundation filed a motion on October 29, 2026, with Judge Sidney H. Stein seeking to submit an amicus curiae brief in the OpenAI copyright case; the brief's main text runs 5,831 words and states that it does not take sides with either party. The brief argues that pretraining of ChatGPT's general-purpose large language models constitutes fair use, but that its RAG feature's reproduction and use of content does not constitute fair use and should comply with license terms such as Creative Commons CC BY-SA 4.0. The Foundation said that if the training stage is not recognized as fair use, AI development may be left only to the best-funded large companies, while recognizing fair use across the board would prompt publishers to lock more information behind walls.
Why read this
AI score 60
Wikimedia argues in the copyright case that pretraining is fair use while RAG is not, offering open-source parties a reference position split in the training data dispute.
Topics
Body
The Foundation’s filing, dated October 29, 2026, and addressed to Judge Sidney H. Stein, is a letter motion for leave to file, with the proposed brief attached as an exhibit and styled as supporting neither party. It was submitted under the court’s local rules and an August 7, 2026 order governing amicus participation, as modified on September 24, 2026; because that order directs prospective amici to move for leave, Wikimedia did not seek the parties’ consent. The proposed brief contains 5,831 words, within the 6,000-word limit the court set for amicus briefs.
Rhett O. Millsaps II of Lex Lumina LLP is counsel of record, alongside the Foundation’s General Counsel Stephen LaPorte, Associate General Counsel Jacob Rogers, and Legal Counsel Aly Marino.
The Foundation argues that a too-restrictive version of fair use could inhibit technological innovation and limit the availability of tools that benefit open-source projects like Wikipedia, while blanket fair use could produce a more closed web in which online knowledge is weakened by a lack of available secondary source material.
In a companion post on Diff, the Wikimedia movement’s blog, the Foundation said that if the training step is not considered fair use, AI development would likely remain possible only for the largest corporations or the best-funded developers, leaving open-source developers unable to afford or even access the technology. A blanket ruling, it said, would instead encourage publishers to lock more information behind barriers, reducing the visibility that Wikipedia and many publishers depend on for readership and for recruiting new volunteers.
CEO Bernadette Meehan said the Foundation is taking a position “to defend the free and open human knowledge that Wikipedia depends on,” describing expanded access to knowledge through AI as a powerful goal that must respect the people, contributors, and communities that make reliable knowledge possible.
The proposed brief grounds its approach in the Supreme Court’s 2023 decision in Andy Warhol Foundation for the Visual Arts v. Goldsmith, arguing that each distinct use of copied works across the stages of developing and operating a chatbot requires its own four-factor fair-use analysis. It cites the 2025 Bartz v. Anthropic ruling as instructive for assessing separate uses of the same copies at different stages rather than blending them into a single analysis.
The brief describes retrieval-augmented generation, or RAG, as a process in which a chatbot searches the web or another database, then identifies, copies, ranks, and pastes relevant chunks of content into the model’s context window alongside the user’s query. Because such a system uses the works for their original purpose of informing readers, takes the most important parts of those works, and competes with the sources for human viewership, the brief argues, the use likely fails the four-factor test.
The Foundation maintains that RAG and similar grounding techniques should not be treated as fair use and that companies offering them should respect each platform or publisher’s licensing terms. In Wikipedia’s case, that is the Creative Commons CC BY-SA 4.0 license, which requires credit to original creators and requires that adaptations remain under the same license.
The brief’s conclusion asks the court to rule that the pre-training of ChatGPT’s general-purpose LLM was fair use, while OpenAI’s use of copies in ChatGPT’s retrieval-augmented generation feature is not fair and must abide by licenses such as the Creative Commons license for Wikimedia Project content.
Wikipedia holds more than 67 million articles across 300 languages, with nearly 250,000 volunteers contributing each month, and the Foundation describes it as one of the highest-quality datasets used to train LLMs. The brief states that more than 260,000 volunteer contributors per month, as of January 2025, create and moderate content across the Foundation’s thirteen free-knowledge platforms, and that Wikipedia is viewed billions of times per month.
General Counsel Stephen LaPorte said the fair-use conversation “cannot be limited to for-profit organizations,” adding that a ruling that does not apply fair use principles carefully could threaten the sustainability of free knowledge and stifle the development of open-source technologies.
Wikimedia’s motion joined a wave of amicus activity: docket entries show that on October 28 and 29, 2026, Engine Advocacy, the Authors Alliance, Public Knowledge, Professor Matthew Sag, Brian L. Frye, Digital Content Next, and a group of publishing organizations including the Association of American Publishers moved to file their own amicus briefs, while summary-judgment briefing between the news publishers, OpenAI, and Microsoft continued. The court has broad discretion to decide whether to accept an amicus brief, the Foundation’s filing notes, and Judge Stein must grant the Foundation leave before its proposed brief is formally accepted.