Found this article article by Ron Paul on NAIS. Here's the money quote:
In typical Washington-speak, NAIS is “voluntary” – provided USDA bureaucrats are satisfied with the level of cooperation. Trust me, NAIS will be mandatory within a few years. When was the last time a new federal program did not expand once implemented?
Further on down the line-and more important: I hear they are already putting microchips in soldiers to monitor their whereabouts. How soon will they be slipping them under the skin of newborns in the hospitals so everyone can be tracked?
Oremus pro invicem!