[serf]

buying the thing doesn't do that.

abusing the thing in the wrong region does.

question : why isn't this a matter of national import/export control? Why is that duty falling onto Amazon?

if Amazon was selling black-tar heroin I would have more questions than "Why is Amazon selling this? How dare they."

[bigfatkitten]

Because Amazon has a legal duty under consumer law to only sell goods which are fit for purpose, be of acceptable quality etc. It would be hard to describe a thing that is unlawful to use in the market it was sold as being fit for purpose.