Brief

Microsoft’s Fable 5 restriction keeps Anthropic retention questions in play

Microsoft limited employee use of Anthropic’s Claude Fable 5 over data-retention concerns while legal teams evaluated changes, according to Reuters, citing The Verge. Reuters also reported that Anthropic’s Mythos-class policy retains prompts and outputs for 30 days for trust-and-safety purposes on every platform where those models are offered, while Anthropic support material in the research pack says retained data is assessed by automated safety systems and protected under its security program and agreements. The evidence supports a privacy-versus-safety tradeoff for enterprise users, but not the stronger claim that Anthropic has overridden existing zero-retention contracts. The key unresolved issue is whether Fable 5 access requires new retention terms for enterprise and API customers, or whether existing customers can remain under prior zero-retention arrangements by contract or model choice.

AI · June 13, 2026