Anthropic says new defenses cut Claude distillation 90-99%

On Oct. 12, 2026 Anthropic said new safeguards cut the Claude reasoning tokens distillers could extract on its own platform by about 90 to 99 percent, a 10- to 100-fold drop, with a stated false-positive rate under 0.1 percent. The classifier runs on Claude Sonnet 5.5, Opus 5 and 5.5, and Fable 5 and 5.1. Anthropic also said Zhipu distilled cyber capabilities from leading US models while building GLM-5.3. That allegation is Anthropic's and was not independently confirmed in this pass. Al Jazeera reported the 90-99 percent figure.