Comment by UK AI Security Institute

Open-weight systems are the lifeblood of open research and innovation in AI. They increase transparency, allow for widespread red teaming, and decrease market concentration. However, open-weight models also pose unique risks. They can allow harmful AI capabilities to proliferate rapidly and irreversibly. Just as they can be modified for beneficial uses, they can also be modified for harmful ones. Safeguards designed to prevent harmful behaviours can also be quickly and cheaply removed from open-weight models. If a model is deployed with closed weights, its deployer can draw from a rich toolkit for making it safer. For example, they can scaffold the model with safeguards such as content filters. They also fully control the points of access, allowing them to enforce acceptable usage policies.