Encyclopedia Britannica and Merriam-Webster Sue OpenAI Over Alleged Copyright Infringement

The lawsuit claims ChatGPT used nearly 100,000 copyrighted articles to train its AI models.

Mar. 17, 2026 at 1:03pm

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Encyclopedia Britannica and its subsidiary Merriam-Webster have filed a lawsuit against OpenAI, the maker of ChatGPT, alleging that the AI company copied their copyrighted content without authorization to train its large language models. The lawsuit, filed in Manhattan federal court, claims that ChatGPT responses frequently reproduce or closely paraphrase Britannica's reference content, including encyclopedia articles and dictionary entries.

Why it matters

This lawsuit highlights the ongoing tensions between AI companies and content creators over the use of copyrighted material in model training. Britannica and Merriam-Webster argue that ChatGPT's use of their content deprives them of subscription and advertising revenue that funds their content creation.

The details

The complaint alleges that OpenAI used close to 100,000 Britannica articles to train its models, and that ChatGPT responses frequently reproduce or closely paraphrase Britannica's reference content. The plaintiffs also claim that OpenAI uses a retrieval-augmented generation system to pull from Britannica's content in real time when generating responses, which they argue substitutes for visits to their websites and deprives them of revenue.

  • The lawsuit was filed in Manhattan federal court last week.

The players

Encyclopedia Britannica

A leading reference publisher and content creator, which is suing OpenAI over the alleged use of its copyrighted content to train ChatGPT.

Merriam-Webster

A subsidiary of Encyclopedia Britannica and a co-plaintiff in the lawsuit against OpenAI.

OpenAI

The artificial intelligence company that created the ChatGPT language model, which is accused of copyright infringement in the lawsuit.

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What they’re saying

“Our models empower innovation, and are trained on publicly available data and grounded in fair use.”

— OpenAI spokesperson

What’s next

The lawsuit is moving through the courts, and a separate Britannica case against AI search company Perplexity AI, filed last year, is also ongoing.

The takeaway

This case highlights the ongoing legal battles between AI companies and content creators over the use of copyrighted material in model training, and the potential impact on the revenue streams of traditional publishers like Britannica and Merriam-Webster.