Anthropic, the American AI lab, has claimed in a letter to the U.S. Senate that Chinese AI tech giant Alibaba illicitly used Claude to train its own models, with violations occurring from April to June 2026. The company sent the letter to Sen. Tim Scott and Sen. Elizabeth Warren before a scheduled hearing on AI issues. Anthropic stated that Alibaba used 25,000 fake accounts and 28.8 million exchanges to illicitly distill its Claude model. This method, called distillation, allows competing labs to build models at “a fraction of the time, and at a fraction of the cost” of independent development. Anthropic traced the campaign to operators connected to Alibaba and Alibaba Qwen, its AI lab, and warned that distillation may help China create a frontier AI model matching Mythos Preview’s capabilities. Earlier this year, Anthropic accused DeepSeek, Moonshot, and MiniMax of using 24,000 fraudulent accounts and 16 million exchanges collectively for similar distillation.