For a fun example to talk about look at Deadmau5’s Purrari.
The Nyan cat wrapped Ferrari.
Legally Ferrari had little they could do. There was some things to do with putting a modified badge they could stop. While on finance they could recall the loan due to the modifications affecting the equity in the car.
But any seller of any product has the backstop that they can ban further purchases and refuse future services. Or even potentially be required to buy their home nation.
Why would Nitrogen gas suppliers not want this?
As a global company, do you want to risk losing a major market by supplying a product for executions.
If you sell your product for executions you are officially selling a poison.
Do you want the regulation involved to have to background check every customer to ensure they are not using it for lethal purposes?
Do you want the additional import and export controls on your product?
Are you held liable in any way if someone deliberately uses your product for euthanasia or suicide? Potentially. That’s why several countries have limits on the volume of paracetamol an individual can purchase.
The Terms of Service is a sticking plaster, probably not even enforceable, but the bare minimum to avoid further regulations on the industry. But it’s certainly worth nitrogen gas suppliers trying to avoid themselves being dragged into a hornets nest of politics, morality, and costly regulation.
Banning a small customer, in prisons, from buying your product could save you a lot of money in the long run.