Anthropic accuses Alibaba’s Qwen lab of the largest known “distillation attack” on Claude
In a letter to the US Senate Banking Committee that became public this week, Anthropic accused Alibaba’s Qwen AI lab of running what it calls the largest known distillation attack against Claude — using roughly 25,000 fraudulent accounts and about 28.8 million interactions between April 22 and June 5 to extract Claude’s most advanced software-engineering and agentic-reasoning capabilities. Distillation here means systematically prompting a rival model and training on its outputs to copy its behavior, which Anthropic says violated its terms. Senators responded by floating an amendment to sanction foreign firms found improperly accessing US model outputs.
Why it matters: Distillation is a legitimate, widely used technique — but doing it to a competitor’s model at industrial scale and against its terms turns a training method into an alleged theft of capability. The dispute drags model-output IP and US-China AI competition squarely into Washington, and could reshape what labs are allowed to learn from each other.