Anthropic accused Alibaba Group Holding Ltd. of orchestrating a large-scale campaign to extract capabilities from its Claude AI models. According to a letter reviewed by Reuters, Anthropic wrote to U.S. lawmakers—including Senator Elizabeth Warren and Senator Tim Scott—alleging that operators affiliated with Alibaba and its AI research unit, Qwen, conducted a large-scale “distillation” campaign between April 22 and June 5, 2026. Anthropic alleged the effort relied on nearly 25,000 fraudulent accounts that collectively produced more than 28.8 million exchanges with Claude, aimed at accelerating China’s ability to develop AI systems approaching the capabilities of Anthropic’s advanced Mythos Preview models. Alibaba and Anthropic did not immediately respond to requests for comment. At the time of publication, Alibaba shares are trading 2.79% lower at $97.01.