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.

Spokespeople for the companies did not immediately respond ​to requests for comment on the complaint on Monday.

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.