[David Sacks: Government Forced to Regulate After Anthropic's Fable Model Security Vulnerability Went Unfixed] David Sacks, co-chair of the U.S. President's Council of Advisors on Science and Technology, shared his views on the incident involving Anthropic's suspension of access to Claude Fable 5 and Mythos 5 for foreign nationals in a tweet after discussions with individuals inside and outside the government. Earlier this week, Anthropic publicly released its Mythos-grade model under the commercial name 'Fable.' 'Fable' is a 'Mythos' model equipped with safety measures. A highly trusted partner of both Anthropic and the U.S. government discovered a method to bypass these safety measures during testing of 'Fable.' Administrators demanded that the vulnerability be fixed, or the model would have to be taken down, but the request was refused.