The lawsuit in a California state court represents the latest front in the growing battle between content providers and AI companies over the use of data to train increasingly sophisticated language models that power the generative AI revolution.

Anthropic, valued at $61.5 billion and heavily backed by Amazon, was founded in 2021 by former executives from OpenAI, the creator of ChatGPT.

The company, known for its Claude chatbot and AI models, positions itself as focused on AI safety and responsible development.

"This case is about the two faces of Anthropic: the public face that attempts to ingratiate itself into the consumer's consciousness with claims of righteousness and respect for boundaries and the law, and the private face that ignores any rules that interfere with its attempts to further line its pockets," the suit said.

According to the complaint, Anthropic has been training its models on Reddit content since at least December 2021, with CEO Dario Amodei co-authoring research papers that specifically identified high-quality content for data training.

The lawsuit alleges that despite Anthropic's public claims that it had blocked its bots from accessing Reddit, the company's automated systems continued to harvest Reddit's servers more than 100,000 times in subsequent months.

Reddit is seeking monetary damages and a court injunction to force Anthropic to comply with its user agreement terms. The company has requested a jury trial.

In an email to AFP, Anthropic said "We disagree with Reddit's claims and will defend ourselves vigorously."

Reddit has entered into licensing agreements with other AI giants including Google and OpenAI, which allow those companies to use Reddit content under terms that protect user privacy and provide compensation to the platform.

Those deals have helped lift Reddit's share price since it went public in 2024.

Reddit shares closed up more than six percent on Wednesday following news of the lawsuit.

Musicians, book authors, visual artists and news publications have sued the various AI companies that used their data without permission or payment.

AI companies generally defend their practices by claiming fair use, arguing that training AI on large datasets fundamentally changes the original content and is necessary for innovation.

Though most of these lawsuits are still in early stages, their outcomes could have a profound effect on the shape of the AI industry.