Cybersecurity researchers are complaining that Anthropic's new model Fable has guardrails that are too strict for any cybersecurity work.[986066][993053] Anthropic is releasing Claude Fable 5, its first Mythos-class model available to the public. The model comes with guardrails that block responses in high-risk areas like cybersecurity and biology.[964801][977742] The company requires 30 day data retention for Fable and Mythos models, sparking concerns over potential privacy issues.[993061][959753]