Right now. But we all know this can and will be corrected. Then what?
Well, "then what" is the big question now isn't it. The article falls short in that it seems to conflate "undetectable" with "untraceable". If undetectable is what we're worried about then the problem will pretty much solve itself since any firearm would have to use metal or possibly carbon fiber to be reliable and safe for more than a few rounds. Both those materials are detectable (quick aside - the TSA found about a half-dozen or so of these 3d printed guns in the past year). If the issue is untraceable then it would seem what they want is a serial number attached to the "gun" part so they can trace it with the defacto registry they're not supposed to have. I suspect this is the more likely case given anti-gun activists these days.
@AbaraXas and
@roamer_1 are both right about the first amendment part of the issue and you'd like to think that would be a settled issue but I'm guesing the left will continue to push for penalties despite clear first amendment implications.
This is just like the plastic gun scare in the 80's when Glocks first hit the market - and just as dumb, but of course, that never stops the left from persuing their authoritarian agenda.