Operators linked to Alibaba and its AI lab Qwen have conducted a large-scale campaign to distill Claude. This was stated in a letter from Anthropic to U.S. Senate Banking Committee Chairman Tim Scott and senior Democrat Elizabeth Warren, as reported by Reuters.

The company described the incident as the largest known distillation attack. According to the agency, from April 22 to June 5, over 28.8 million interactions with the model were created through nearly 25,000 fake accounts.

"Aside from its scale, this campaign was striking due to its brazen nature [...]. Alibaba is listed on the New York Stock Exchange, operates business in the United States, and is accountable to American investors and regulators," the letter stated.

In February, Anthropic noted that the distillation method is often used legitimately, for instance, to create a cheaper or more compact version of a model. The problem arises when competitors gain access to advanced tools through fake accounts, circumvent service restrictions, and use the responses to train their own systems.

In the letter, Anthropic claims that the alleged campaign targeted Claude's capabilities in agent tasks, software development, and long-term planning. The developer believes such actions allow for the replication of a leading model's behavior without the costs of training it.

"When Chinese laboratories distill these capabilities from American models, they reap the benefits of American investments without incurring the costs and risks associated with training advanced AI models. This undermines the economic logic that underpins U.S. leadership in AI, turning billions of dollars in research and development, computational resources, and other American investments into a subsidy for our competitors," emphasized Anthropic.

Company representatives also pointed out that unauthorized distillation could accelerate the development of Chinese AI systems for cyber operations, military tasks, and intelligence.

What Anthropic is Asking from Congress

According to Decrypt, Anthropic has urged lawmakers to expand the sharing of technical indicators and intelligence between developers of advanced AI models and the U.S. government. The company also requested clarification of antitrust rules to allow firms to share information about such attacks without risking violations of competition laws.

Another part of the proposals concerns export controls. Anthropic demanded stricter restrictions on advanced AI chips and computational resources, as well as closing loopholes that allow Chinese organizations to access foreign data centers. The company suggested imposing sanctions or other measures against parties responsible for large-scale extraction of model capabilities.

Other Cases

In February, Anthropic accused DeepSeek, Moonshot AI, and MiniMax of generating over 16 million interactions with Claude through approximately 24,000 fake accounts. At that time, the developers claimed to have linked the campaigns to specific labs based on IP addresses, request metadata, infrastructure indicators, and, in some cases, data from partners. DeepSeek generated over 150,000 interactions, Moonshot AI over 3.4 million, and MiniMax around 13 million.

These accusations sparked controversy, as distillation remains a common industry practice. In April, as noted by Decrypt, Elon Musk testified in federal court that xAI "partially" used OpenAI models to train Grok.

On April 20, Congressman Bill Huizenga introduced a bill against the extraction of key technical characteristics of closed American AI models by foreign adversaries. According to the Congressional Budget Office, the document includes export restrictions and sanctions against foreign entities that illegally access AI-based products.

It is worth noting that in December 2025, Nvidia announced the development of technology to verify the location of its processors amid reports of smuggling accelerators into China.