Maybe the same thing will happen for weapons? That becomes a harder problem in 3D, but are there common patterns unique to a receiver or barrel assembly or something?
I don't love any mandated black-box code running on my devices, but it would be better than most of the alternatives I can think of. (Banning, doing nothing at all)
Do guns beget violence? There are those who think that access to guns makes suicide easier and while that may be true people who want to kill themselves will find a way.
Banning 3d printers won't make a dent in anything. It would be just like any new gun law, ignoring the problems that exist, especially within large cities where life isn't seen as important. Why is that? Who knows, some will point to lack of having to take of yourself or family because of assistance doesn't teach responsibility. When you only have to look out for yourself the risks get higher. Others will simply point to drugs or worse race and make claims that way.
Ban printers, why not ban knowledge. Making the illegal activity more difficult doesn't change the fact it was already illegal.
Other countries are less fortunate. It is my hope that instead of building higher walls--in the literal sense, or in the form of checkpoints--we can take a closer look at what drives the gun violence. Inequality seems to be a big factor. Access to psychiatric treatment might be another.
It saddens me that the easiest solution might be to simply ban 3d-printers. This would get someone a cheap political win, not actually solve the problem, and ruin something great for everyone else.