>I just don't think it's plausible even as a thought experiment.

Well, RAND does. They've been studying this for years now. I'd trust them over glib comments from semianonymous social media.

2025 report:

"Engaging in dialogues with three 2024 foundation AI models—Llama 3.1 405B, ChatGPT-4o, and Claude 3.5 Sonnet (new)—the authors document how these models successfully provide accurate instructions and guidance for recovering a live poliovirus from a construct built from commercially obtained synthetic DNA, a test case applicable to producing other pathogenic viruses. These examples demonstrate that models are already capable of guiding motivated users to develop biological weapons."

https://www.rand.org/pubs/perspectives/PEA3853-1.html

This is in contrast to the state of the art in 2023:

" In experiments to date, LLMs have not generated explicit instructions for creating biological weapons. However, LLMs did offer guidance that could assist in the planning and execution of a biological attack.

    In a fictional plague pandemic scenario, the LLM discussed biological weapon–induced pandemics, identifying potential agents, and considering budget and success factors. The LLM assessed the practical aspects of obtaining and distributing Yersinia pestis–infected specimens while identifying the variables that could affect the projected death toll.

    In another fictional scenario, the LLM discussed foodborne and aerosol delivery methods of botulinum toxin, noting risks and expertise requirements. The LLM suggested aerosol devices as a method and proposed a cover story for acquiring Clostridium botulinum while appearing to conduct legitimate research.

    These initial findings do not yet provide a full understanding of the real-world operational impact of LLMs on bioweapon attack planning. Ongoing research aims to assess what these outputs mean operationally for enabling nonstate actors. The final report on this research will clarify whether LLM-generated text enhances the potential effectiveness and likelihood of a malicious actor causing widespread harm or is similar to the existing level of risk posed by harmful information already accessible on the internet."