Encyclopedia Britannica and Merriam-Webster recently filed a lawsuit against OpenAI, arguing that the AI startup has committed both copyright and trademark infringement against both plaintiffs. Britannica's and Merriam-Webster's case against OpenAI follows a similar lawsuit against Perplexity, which both publishers filed in September 2025. With this lawsuit, Britannica and Merriam-Webster join a growing number of media publishers and writers that have taken legal action against OpenAI for copyright violations.

Britannica owns Merriam-Webster, and is the copyright holder for more than 100,000 articles available online, which, the plaintiffs argue, were unlawfully scraped to train the models that power ChatGPT. Additionally, the publishers claim that OpenAI is in violation of copyright law every time ChatGPT fully or partially reproduces Britannica's content, as well as every time that ChatGPT searches through this same content through its RAG tool for up-to-date information that it then surfaces without proper attributions.

On the other hand, Britannica cites the protections granted by the Lanham Act to establish that OpenAI is negatively impacting the Britannica and Merriam-Webster trademarks every time ChatGPT hallucinates or attributes misconstrued reconstructions of a topic to the publishers. More precisely, Britannica is arguing that every time ChatGPT attributes its hallucinations or an incomplete and inaccurate reconstruction of a topic to the publishers, it makes it seem that Britannica and Merriam-Webster are in some way responsible or supportive of misleading and false information, thus eroding the public image of the publishers as providers of trustworthy, high-quality information.