Not unexpected information, but at an unexpected place.
Instapundit references Mother Jones, which published an article about building an AK-style rifle.
The author gives a short description of a build-party he attended, and mentions some details of the process. But he doesn't mention enough to allow many readers to reproduce the process themselves. However, it's not as if such info is hard to find.
It's a process I've heard about, and may do myself one of these years. The weird part is that the market for AK parts-kits (plus barrels) clears at roughly the same price as professionally-manufactured AK rifles. Thus, I pay the same cost either way.
However, if I were to build my own rifle, it would be mine in a way that a purchased rifle would not be.
There was a lot of attention given, recently, to the concept of building a home-made firearm from a 3D-printer. While such things may be of interest, it is worth remembering that expensive, computer-controlled tools are not necessary to build an AK-47 rifle from a parts-kit.
I strongly doubt that either process is likely to see much use by criminals in America. There is apparently a large number of firearms already in the black and gray markets. From data gathered by the Dept. of Justice, most of those firearms are pistols. Many were stolen, or purchased through intermediaries who don't mind re-selling to prohibited persons.
The article at Mother Jones was informative, though I doubt the wisdom of the man destroying his firearms so soon after building it. He should spend time learning the strengths and limitations of the tool.