From next week Amercans are going to be able to print 3D guns - scary or what?

Not really,and it isn't like anyone can just do it. Besides gun design is no big secret, the only thing these offer is turning the dimensions into G code for CNC mills and coding for 3D printers. This isn't really anything someone could not have done with machinist lathe and mill.
It is the right decision from a freedom of knowledge and speech stance.