When I wrote an article for FSM a few years ago about 3D printing it was a big topic in the open-source community but it had not yet gone fully mainstream. If there was one thing guaranteed to make 3D printing explode onto the mainstream news media it was an item about someone "printing" a gun. That got your attention, didn't it? Mine too. It's controversial of course but it might just be the beginning of a rerun of the Napster/Piratebay episodes in the 21st century - with the inevitable debate between patent-free, non-hierarchical open-source models and patent-encumbered proprietary software and hardware. Napster was a ripple. 3D printing will be a tsunami.