The thing about a gun is that it often takes 'only' one shot to cause serious issues.

I am one American who hopes they will find ways to curtail ANY easy way to mass-produce weapons. (Those printers have to programmed.... could it be possible to build in restrictions on certain shapes? ...just brainstorming)

Right now they are limited to certain plastic/resin items........ but you can bet there are guys experimenting with adding other materials to the mix.