The core safety-related arguments for closed weights are:

1. Visibility. API providers can monitor for misuse, and regulators only need to oversee a few centralised players. Once weights are released, anyone with sufficient hardware (foreign governments, criminal groups, terrorists?) can run them and monitoring is no longer feasible.

2. Revocability and containment. If closed-weights models are found to be dangerous, access can be withdrawn. Deployments that are autonomously causing harm are easier to contain.

3. Guardrails. Safety fine-tuning and classifiers can be removed from open-weights models, enabling harmful use that would not be possible via API.