Not only blatant sensationalism - nothing new risk wise.
During WWII the British produced more than a million Sten sub-machine guns from bicycle and muffler shops using sheet metal and common tubing. From a risk only standpoint - there are many similar firearm designs available today that require no serious machining ability, just some hand tools and basic hardware store materials that can produce fully automatic firearms - with far less money and technology than that of 3-D printing. Also, consider that 3-D printing is limited to a very small number of very specific and purified materials not widely available and some materials necessary for firearm production totally unavailable for 3-D printing. Parts such as springs, sears and gun barrels require metallurgical processes (tempering) that can't be printed in finished form and require other technologies to produce.