US frontier labs face criticism for pushing ban on open-source AI

The biggest names in American tech are drawing a line in the sand over open-source AI, and it’s not where you might expect. On July 24, a coalition of 25 companies including Nvidia, Microsoft, and Meta published an open letter titled “Open Weights and American AI Leadership,” pushing back against what they describe as a coordinated effort by certain frontier labs to restrict open-weight AI models in the US.

The letter’s core argument is blunt: banning open-weight models wouldn’t make America safer. It would make America slower.

The coalition’s case against restrictions

The signatories argue that restricting open-weight AI models would effectively hand a competitive gift to closed-model labs while doing nothing to address the real competitive threat, which is the proliferation of Chinese AI systems that are already gaining traction globally.

Chinese open-weight models like Moonshot AI’s Kimi K3, a 2.8 trillion-parameter system, have been benchmarking competitively against top US closed models.

OpenAI initially declined to sign, which raised eyebrows given CEO Sam Altman’s occasional gestures toward openness. Under rising public scrutiny, OpenAI eventually joined the coalition.

Anthropic held firm in not signing. The company said it opposes an outright ban on open-weight models but prefers targeted actions against intellectual property theft rather than broad industry pledges.