Obviously, the moral thing is to make your own. ;-)

Mass-production, however, has some interesting advantages. It's harder to trace it back to its owner, for instance.

quite the opposite. it makes it rather easy to cross-reference amazon orders of said mask with politically active online accounts via isp records to identify suitable candidates for future re-education internment camps on the topic of IP and state rights. could be done using the ironically libertarian-funded Palantir, i suppose.

You could also purchase it locally with cash at a costume/mask shop...

Extra points if you buy a fake version made in China and brought illegally into your country of choice.

I'm as tinfoily as the next guy, but I don't think buying a mask on amazon is going to land you in a reeducation camp. Wearing a mask hardly makes one a Ted Kaczynski.

The point is if you DO turn out to be a Ted Kaczynski, having these kinds of purchase records on file make it easier to find you.