Anthropic sends complaint letter against Chinese company Alibaba, accuses it of creating fake accounts to steal Claude capabilities by ...

Anthropic is once again accusing Chinese companies of stealing capabilities of its AI models. America's frontier AI lab has accused Chinese giant Alibaba of illicitly extracting its Claude AI model capabilities in what it said was the largest known attack of its kind on the company.

Anthropic sent a letter to the US Senate Committee on Banking, Housing, and Urban Affairs accusing the Chinese tech company Alibaba of “brazenly” and “illicitly” attempting to extract its artificial intelligence capabilities.The letter, which was addressed to Senators Tim Scott, R-S.C., and Senator Elizabeth Warren, D-Mass, on June 10, said that Alibaba carried out “the largest known distillation attack on Anthropic to date.”

Anthropic claimed in the letter that companies affiliated with Alibaba and its AI lab carried out 28.8 million exchanges with its models using roughly 25,000 fraudulent accounts between April 22 and June 5. “We believe combating the threat of illicit distillation requires coordinated action between government and industry, and we will continue working with Congress and the Administration to maintain American AI leadership,” an Anthropic spokesperson said in a statement.

What is Distillation that Anthropic keeps accusing Chinese companies ofDistillation is an AI training method where a small, less capable model is built using outputs from an existing, stronger model. The letter describes "distillation" effort as something that involves training a less capable model on the outputs of a stronger one. Anthropic said in the letter that distillation is a way to help accelerate China's ability to reach Anthropic's advanced Mythos Preview capabilities.

Anthropic made China complain in February 2026

This is not the first time that Anthropic has complained about China. In February this year, Anthropic said that it had identified a campaign by Chinese AI startup DeepSeek — whose low-cost AI model sent shockwaves through the technology world in January 2025 — and two other Chinese AI labs to illicitly extract capabilities from its Claude AI platform. It said that DeepSeek's operation involved over 150,000 exchanges, while Moonshot AI was at a scale of over 3.4 million and MiniMax over 13 million.The company further said at the time that the campaigns were growing in "intensity and sophistication" and that addressing the threat would require "rapid, coordinated action among industry players, policymakers and the global AI community."

Alibaba sues Pentagon over ban

Alibaba was recently added to the Pentagon's Chinese military companies list this month, a designation that the company is challenging. Alibaba Group has sued Pentagon to be removed from the blacklist.

The Chinese e-commerce giant has appealed to the US justice system to avoid a designation the company says is arbitrary and unjustified. In its court filing, the Hangzhou-based company has argued that the Pentagon has linked the company to China's People’s Liberation Army (PLA) without providing substantial evidence or explanation.

It terms the ban by the Pentagon based on alleged ties to PLA a violation of constitutional due process and of the Chinese company’s right to free speech.Alibaba said in the complaint that its inclusion in the 1260H list now prevents the company from retaining certain lobbyists that have represented the company for years. This, the company said, includes lawyers and advocates that it needs to challenge the military-supporter label. It further argued that there is a lack of constitutional due process by the US government as it learned about its designation as a Chinese military supporter by reading the Federal Register.