And in fact alot of the stuff he tell the reader to google (VIPR, fusion centers, facial recognition, email searchs) these are all very real and happen every day.
The one thing I would differ in conjecture upon would be the idea that law enforcement officers would be carrying out disarming of the public IF it ever came to that in the USA. If it came to such a thing, I belief the fed would do any such forced disarming sweeps with the military; possibly under the direction of the BATF or some other alphabet agency, but the contact would be made by men and women in the armed forces.
Whether by domestic LEOs or military, the people enforcing the confiscation will be (a) people who took an oath to defend against all enemies foreign and domestic, and (b) people who are breaking that oath by the act of confiscation. They will be traitorous pawns, but traitors nonetheless. They will, no doubt, succeed on the first several attempts. Then the ambushes and counter attacks will start.