He is all for the voluntary implant of them by choosing parents.
What he doesn't seem to want to discuss is the logical conclusion to such a course of action. Just as with Social Security numbers, which were never intended to be a form of national identification, and just as with the Social Security system itself - that to this day is legally voluntary (and how many Americans know that?) - every child born in America will soon be assigned their microchip implant before leaving the birthing room.
Sean seems to have forgotten the words and the doctrine of Ben Franklin:
The man who will sacrifice a little liberty for a little safety deserves neither.
(I forget the exact quote; maybe another FReeper can help me out here.)