Britannica and Merriam-Webster Sue OpenAI for Copyright and Trademark Infringements

Encyclopaedia Britannica and its subsidiary Merriam-Webster filed a sweeping copyright and trademark lawsuit against OpenAI on March 13, 2026, in the U.S. District Court for the Southern District of New York.

“Encyclopaedia Britannica Inc”

Bloomberg Law News

The complaint accuses OpenAI of using nearly 100,000 Britannica articles as training data for its large language models without permission or compensation.

Bloomberg Law News

Then the lawsuit alleges that OpenAI generates responses that reproduce or closely mirror that material, thereby undercutting the publisher's business model.

The lawsuit represents another major escalation in the battle over AI training data, coming at a particularly sensitive moment for OpenAI.

OpenAI is already fighting multiple copyright battles with The New York Times, authors including John Grisham and George R.R. Martin, and visual artists.

The legal action mirrors a similar lawsuit the same companies filed against AI search engine Perplexity AI in September 2025.

This indicates a coordinated strategy to challenge AI companies' use of reference content.

The core copyright infringement allegations center on OpenAI's systematic scraping of Britannica's proprietary content to train its AI models.

This was followed by the unauthorized reproduction of that material in ChatGPT responses.

Engadget

Britannica asserts that OpenAI scraped close to 100,000 articles from its databases to train the company's large language models without permission.

The complaint provides side-by-side comparisons showing that ChatGPT outputs near-verbatim reproductions of Britannica articles.

These include dictionary definitions, structured examples, and usage notes that Britannica and Merriam-Webster regard as protectable editorial expression.

The lawsuit specifically notes that GPT-4 itself has 'memorized' much of Britannica's copyrighted content.

It outputs near-verbatim copies of significant portions on demand, with these unauthorized copies being used to train their models.

Uniquely among AI copyright disputes, Britannica added a Lanham Act trademark claim.

“Encyclopaedia Britannica, the parent of Merriam-Webster, has filed a sweeping lawsuit against OpenAI, accusing the company of large-scale copyright infringement and false attribution tied to its AI systems”

FindArticles

This claim asserts that ChatGPT sometimes hallucinates articles or quotes and attributes them to Britannica or Merriam-Webster.

This false attribution, the suit argues, confuses users about the origin and accuracy of information.

It risks reputational harm for brands built on reliability.

By presenting AI-generated responses alongside Britannica's and Merriam-Webster's famous trademarks, OpenAI misleads users.

Users might believe Britannica or Merriam-Webster has endorsed or is the source of those responses.

Britannica's reputation rests on accuracy built over more than 250 years.

Associating that brand with AI-fabricated information causes direct reputational harm beyond copyright loss.

Beyond the legal claims, Britannica argues that OpenAI's practices cannibalize its web traffic.

These practices directly compete with Britannica's content, undermining the publisher's advertising-supported business model.

Génération NT

The complaint states that ChatGPT routinely draws on Britannica's content without authorization.

It presents this content in ways that deter clicks through to the source.

This directly competes with Britannica's reference products and advertising-supported pages.

Britannica said OpenAI markets ChatGPT as a way to get 'useful answers on the web' without 'digging through links'.

But Britannica argues ChatGPT provides 'better answers' only by copying copyrighted content.

Britannica reached out about licensing in November 2024, but claims OpenAI 'never seriously pursued licensing'.

OpenAI has defended its position by asserting that its models 'empower innovation, and are trained on publicly available data and grounded in fair use.'

“Encyclopedia Britannica and Merriam-Webster have filed a lawsuit against OpenAI, alleging in its complaint that the AI giant has committed “massive copyright infringement”

TechCrunch

This mirrors the company's standard defense in multiple copyright lawsuits.

TechCrunch

This defense is being increasingly challenged across the legal landscape.

The Britannica case pushes back on the notion that ChatGPT makes fair use of its content.

Britannica argues that the repackaged content has no new expression, meaning or message of its own.

The Britannica lawsuit represents a significant challenge to OpenAI's legal strategy.

OpenAI faces mounting pressure from publishers, artists, and creators who say it built its empire on stolen intellectual property.

Each case chips away at OpenAI's defense that training AI models on publicly available content constitutes fair use.

The Britannica case is particularly significant due to the plaintiffs as trusted reference publishers.