The link seems to disprove your point, the police raided his house.
In the USA it is legal to make your own guns.
> The Legal Framework for Individuals: Making a firearm for personal use is legal. Making a firearm for personal use without a federal manufacturing license is legal. This has always been the case, even after the enactment of the Gun Control Act of 1968 ("GCA"). http://freedomblog.skylarklaw.com/2014/10/is-making-firearm-...
Interesting that this came up in a thread about Bitcoin.
Well, that’s precisely my point. You typically don’t ban anything by physically preventing people from doing it.