By Meghan Bobrowsky

Reddit is suing AI startup Anthropic for using the online-discussion site's data without a licensing agreement, a new front in the battle over how artificial-intelligence companies train their models.

The details

Reddit said the AI company unlawfully used Reddit's data for commercial purposes without paying for it and without abiding by the company's user data policy, according to the complaint, which was filed Wednesday in California.

"Anthropic is in fact intentionally trained on the personal data of Reddit users without ever requesting their consent," the complaint says, alleging that Anthropic's conduct runs counter to how it "bills itself as the white knight of the AI industry."

Reddit, the online discussion forum where users can post anonymously and ask each other questions, has reached formal agreements with both OpenAI and Google to license Reddit's valuable human user data.

Anthropic didn't immediately comment.

The context

Last year, Reddit took steps to try to limit unauthorized scraping of its website, creating a public content policy for its user data that is publicly accessible, such as posts on subreddits, and updating code on its back end.

Reddit said it had tried and failed to reach an agreement with Anthropic, and that it found Anthropic accessing its site after the AI company said it had blocked its bots from doing so.

"Anthropic's bots continued to hit Reddit's servers over one hundred thousand times," the complaint says.

The big picture

Reddit has struck lucrative licensing deals with AI platforms including OpenAI and Google. AI executives have said the Reddit data is uniquely useful in helping to train models given that it hosts conversational interactions between humans. There are more than 100,000 so-called subreddits.

Reddit's lawsuit references a 2021 Anthropic research paper that details the usefulness of Reddit data in AI model training.

Anthropic recently released its latest AI model, Claude Opus 4, which has been well-received by the AI community and scored high on industry benchmarks.

Write to Meghan Bobrowsky at meghan.bobrowsky@wsj.com

(END) Dow Jones Newswires

June 04, 2025 13:25 ET (17:25 GMT)

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