Reddit has filed a lawsuit against artificial intelligence company Anthropic, alleging that the startup scraped its user-generated content without authorization to train its Claude AI models. The complaint, lodged in San Francisco Superior Court, escalates ongoing legal tensions between content platforms and AI developers over data use and licensing.

According to the filing, Anthropic refused to enter a licensing agreement with Reddit despite repeated requests and assurances that it would block its bots from accessing Reddit’s platform. The company’s Claude AI assistant reportedly acknowledged it was trained “on at least some Reddit data” but was unaware whether any of that content had since been deleted.

Reddit alleges that Anthropic’s bots accessed or attempted to access Reddit content more than 100,000 times. The complaint argues this conduct violated Reddit’s policies and resulted in "tens of billions of dollars" in unjust enrichment. By contrast, Reddit notes that it has reached licensing agreements with companies like Google and OpenAI.

Anthropic, whose investors include Amazon, disputes the allegations. “We disagree with Reddit’s claims and will defend ourselves vigorously,” a spokesperson said in response to the suit.

The suit—Reddit Inc. v. Anthropic PBC, No. CGC-25-524892—seeks punitive damages and injunctive relief that would prohibit Anthropic from using Reddit’s data for commercial AI training. Both companies are based in San Francisco, separated by only a short walk.

In a public statement, Reddit Chief Legal Officer Ben Lee said the platform supports an open internet but emphasized that “AI companies must adhere to clear limitations around how they use and monetize content they scrape.”

The case follows Anthropic’s release of its newest Claude models—Opus 4 and Sonnet 4—on May 22. According to individuals familiar with the company, its annualized revenue has now reached $3 billion.