As I was one of the people observing that a serious answer to such a question would draw unnecessary attention to the site, maybe I should expand on my ppoint.
Most of my life I have lived in Greece. Living in Greece is not an intellectual exercise only, though not as dangerous as living in Syria or Egypt at the moment. Living in Athens has meant that ordinary middle class people were caught and suffocated by a fire in a bank, started by a molotov bomb during demonstrations last year. And things will be getting worse rather than better. Now one cannot stop the hot blooded bent on vengeance in making a molotof bomb, since the exercise is simple. But Jeff's question raised the specter for me: how would it be if those masked misguided or guided operators, who intervene in all peaceful demonstrations and turn them into mayhem, could "easily" make a nuclear gun? and instead of five dead people have hundreds and entire suburbs contaminated?
Noting that in most countries it would be illegal to give an instruction manual of point by point creation of a nuclear weapon, the question is also ethical, if somebody used the instructions in the answers provided by the site which resulted in some death and destruction. I think such questions should be closed as not pertaining to physics but to weapons design, and kick the can to another board, engineering or weapons.
Any self respecting government terrorist-hunting organization will be googling such terms and checking on who reads what in this free internet age. Jeff gave a link to an amazon.com book. I am sure all addresses and addressees are carefully scrutinized by somebody that we do not even suspect, from China to North Korea to US. Even Turkey. Can you imagine the Kurdish resistance with a nuclear gun?
The insidious role of the question asked by Jeff is that it asks for a student exercise. An exercise will have numbers and brass tacks, which one cannot find in the run of the mill webpages on nuclear weapons: they waffle and talk of stuff any nuclear physicist knows, not the stuff that needs years of research and tests. Thus the question gave me the impression that it was asked masking a real intention of getting hands on construction instructions of such weapons. That is not innocent or naive. Hence my questioning whether his identity was hacked.