NEW YORK: Encyclopaedia Britannica and its Merriam-Webster subsidiary have sued OpenAI in Manhattan federal court for allegedly misusing their reference materials to train its artificial intelligence models.

Britannica said in the complaint filed on Friday that Microsoft-backed OpenAI used its online articles and encyclopedia and dictionary entries to teach its flagship chatbot ChatGPT to respond to human prompts and “cannibalised” Britannica’s web traffic with AI-generated summaries of its content.

The case is one of many high-stakes lawsuits filed by copyright owners including authors and news outlets against tech companies for using their material to train AI systems without permission. Britannica filed a related lawsuit against artificial intelligence startup Perplexity AI last year that is still ongoing.

AI companies have argued that their systems make fair use of copyrighted content by transforming it into something new.

Britannica’s lawsuit said that OpenAI unlawfully copied nearly 100,000 of its articles to train GPT large language models. The complaint said that ChatGPT produces “near-verbatim” copies of Britannica’s encyclopedia entries, dictionary definitions and other content, diverting users who would otherwise visit its websites.

Britannica also accused OpenAI of infringing its trademarks by implying that it has permission to reproduce its material and wrongfully citing Britannica in false AI “hallucinations.”

Britannica requested an unspecified amount of monetary damages and a court order blocking the alleged infringement.

Published in Dawn, March 17th, 2026