The firm says it withheld an AI model on cybersecurity grounds but sceptics say this was hype to lure investment

This week, the AI company Anthropic said it had created an AI model so powerful that, out of a sense of overwhelming responsibility, it was not going to release it to the public.

The US treasury secretary, Scott Bessent, summoned the heads of major banks for a chat about the model, Mythos. The Reform UK MP Danny Kruger wrote a letter to the government urging it to “engage with AI firm Anthropic whose new frontier model Claude Mythos could present catastrophic cybersecurity risks to the UK”. X went wild.

Others were more sceptical, including the noted AI critic Gary Marcus, who said “Dario [Amodei] has far more technical chops than Sam [Altman], but seems to have graduated from the same school of hype and exaggeration,” referring to the CEOs of Anthropic and its rival, OpenAI.

It is unclear if Anthropic has built the machine god. What is more apparent is that the San Francisco startup widely seen as the “responsible” AI company is brilliant at marketing.