BREAKING: Fable and Mythos have been taken down for security concerns.

TL;DR

• 1

  The shutdown was immediate and sweeping: Anthropic says it received the government directive at 5:21 p.m. Eastern and had to disable Fable 5 and Mythos 5 for all customers because it could not yet verify citizenship status.

• 2

  Foreign nationals are the specific target: The order blocks access by any foreign national, whether inside or outside the US, and even applies to foreign national Anthropic employees, which Theo calls an unbelievable precedent.

• 3

  Anthropic argues the jailbreak was narrow and not unique: According to the statement, the government showed a method that could get Fable to identify minor software vulnerabilities, but Anthropic says other public models, including OpenAI's GPT-5.5, can do the same without a bypass.

• 4

  Fable was already heavily locked down: Theo notes Anthropic had strong cyber safeguards, thousands of hours of red-teaming with the US government and UK AISI, and a new 30-day prompt retention policy that already cost them customers.

• 5

  Theo thinks the policy standard is dangerous: He highlights Anthropic's warning that recalling a commercial model over a non-universal jailbreak would effectively halt new frontier model deployment if applied consistently across the industry.

• 6

  This instantly makes Anthropic's policy writing look prescient: Theo points to Dario Amodei's recent essay on AI's strategic consequences and says the company just got the "fast reaction" from government it had been warning about.