Encyclopaedia Britannica v OpenAI Inc

Encyclopaedia Britannica, Inc. and Merriam-Webster, Inc. v. OpenAI, Inc. (S.D.N.Y., filed March 13, 2026) is a copyright and trademark infringement lawsuit brought by the publishers of Encyclopaedia Britannica and Merriam-Webster dictionary against OpenAI, alleging that OpenAI copied nearly 100,000 Britannica articles and Merriam-Webster dictionary entries (definitions, etymologies, and usage examples) without authorization to train ChatGPT.

Field	Detail
Case Name	Encyclopaedia Britannica, Inc. and Merriam-Webster, Inc. v. OpenAI, Inc.
Court	U.S. District Court, Southern District of New York
Filed	March 13, 2026
Plaintiffs	Encyclopaedia Britannica, Inc.; Merriam-Webster, Inc.
Defendant	OpenAI, Inc.
Claims	Copyright infringement, trademark dilution
Status	Early stages; no motions or rulings reported as of April 2026

Claims

The plaintiffs allege:

• Copyright infringement: OpenAI scraped nearly 100,000 Britannica articles and Merriam-Webster dictionary entries without authorization, license, payment, or notification to train ChatGPT. The scale and commercial nature of the copying challenge any fair use defense.
• Trademark dilution: ChatGPT outputs mimic the style and language of Britannica and Merriam-Webster, potentially misleading users about the source and harming the brands' reputations for accuracy and reliability.

Plaintiffs seek unspecified monetary damages and a court order to block the alleged conduct.

Significance

This case joins over 90 active copyright suits against U.S. AI companies, most filed in the S.D.N.Y. It is notable because it involves reference works (encyclopedia and dictionary content) rather than creative works like books, music, or video, testing whether AI training on factual reference materials constitutes fair use. The trademark dilution claim is also novel in the AI copyright context.

The case also raises questions about hallucinations attributed to authoritative sources: the complaint alleges that ChatGPT generates content falsely attributed to Britannica and Merriam-Webster, potentially damaging the brands' reputation for accuracy.

Procedural History

• March 13, 2026: Complaint filed in S.D.N.Y.
• As of April 2026: The case remains in early stages with no reported motions, responses, or rulings.

See Also

• Gracenote Media Services v OpenAI — Nielsen subsidiary sues OpenAI over copyrighted metadata database
• Kadrey v Meta Platforms Inc — Authors v. Meta over book training data
• Bartz v Anthropic PBC — Landmark AI copyright settlement ($1.5B)
• Cases — Active AI litigation tracker