Anthropic says it cut Claude reasoning token theft by up to 99% in fight against industrial-scale distillation

What happened

The company links the large-scale distillation attacks to Chinese companies Zhipu and Moonshot, and has already banned tens of thousands of accounts. Tens of thousands have already been banned.

Anthropic says it has cut the extraction of Claude's internal reasoning tokens by 90 to 99 percent. Short News Copy the url to clipboard Share this article Go to comment section Anthropic says it cut Claude reasoning token theft by up to 99% in fight against industrial-scale distillation Manuel Uth Oct 13, 2026 Anthropic is battling large-scale distillation attacks on its Claude models. Anthropic is an artificial intelligence company based in San Francisco, and its products and services include Claude and Claude Code.

In these attacks, companies systematically copy an AI model's capabilities to train their own, smaller models . Anthropic says its new defenses have cut the volume of extracted reasoning tokens (the small pieces of text a model reads and writes), the model's internal chain-of-thought steps, by 90 to 99 percent.

Attackers use networks of hundreds of thousands of fake accounts to pull it off. Anthropic names Chinese companies Zhipu and Moonshot as participants.