"It is already understood that you own the output."

I don't think it's settled that anybody owns the output. There seems to be some question whether LLM output can be copyrighted (and there should be).

I'd rather it weren't possible, actually. I think it's better for humanity if we acknowledge that what was legitimately ingested into these models is our collective commons (and what was illegitimately ingested into these models also shouldn't exclusively profit the people who illegitimately did so). I don't know how that squares with the AI industry recovering its trillion dollars in investment, but I reckon they should have thought of that before.