3D printing assault rifles and synthesising Anthrax - should it be allowed?

This year, Defense Distributed released the Ghost Gunner - a $1500 device that allows you to make the lower receiver (critical working part) for an AR-15 semi-automatic rifle (incidentally one of the weapons Martin Bryant used in the Port Arthur massacre). You'd still need to source the other parts but in the US that's comparatively easy compared to buying a full gun.

I've been reading interviews with Cody Wilson, the founder of Defense Distributed. He's a fascinating guy - former law student and now a crypto-anarchist who wants to shake up the government and restore power to the people. WIRE listed him as one of one the world's most dangerous people.

On the one level, I think what he's doing is positive because it draws attention to the issue. There's a good chance that criminals were already doing/planning to do what he was doing and now governments have been forewarned (the UK government has already banned 3D printing weapons).

On the other other, I am definitely not a fan of gun 'uncontrol'. I wholeheartedly support Obama's plans to use his executive powers to limit access to guns. The world doesn't need more people with a chip on their shoulder and a force-multiplier in their bag.

Can we actually stop this?
For the moment, Defense Distributed seems to face a large number of issues getting its CNC machine to market. Major freight companies like UPS are refusing to ship the Ghost Gunner, California has already moved to ban 'ghost guns' without serial numbers and other governments (including Australia) are putting a ban on 3D printing/home manufacturing weapons completely.

But as in-situ manufacturing technology improves, I wonder if those measures will matter anymore. In a few years, 3D printing technology will get to the point where shipping will no longer be necessary. Download a design off the dark net and a few hours later, you'll be able to print out a working assault rifle without any knowledge from the authorities.

Guns aren't the only threat. Bio hackers will soon have the technology to grow weaponised anthrax using state of the art DNA synthesis machines.

In my opinion, there is no way to stop this from a technological perspective. If someone seriously wants to kill, they're going to find a way.

The bigger picture
I think we need to look at the bigger picture. Why are there so many mass shootings in the US? Is it only because of the availability of guns? There's evidence to suggest that other macro factors have a greater influence. People don't just get murdered by guns - stabbings, blunt objects, strangulation, you name it - US citizens seem to like killing each other. Why? Income inequality. A massive rich poor divide and lack of an adequate social security network leads to crime.

If we want to stop people from shooting each other with home CNC-milled semi-automatic rifles and poisoning each other with weaponised anthrax grown in a DIY-bio lab, we should look at the root causes of why they feel so disenfranchised in the first place.

Rather than issuing every citizen with a bulletproof vest and an oxygen mask, I think we need to invest in better social support policies and early intervention mental health programs.