How 3D printers will revolutionise the manufacture of deadly weapons

In the very near future, someone will be killed with a gun not bought from a dealer or a dodgy bloke in a pub, but printed at home in metal and plastic with a 3D printer. The tools necessary to replicate a deadly weapon will soon be affordable to someone toiling away at home. [The slant may be anti-gun, OMG! Someone could get killed! (Yeah, like an armed intruder!), but the technology is very cool. Same slant/cool goes for the video at the War News Updates link.]