I see.

So why is it that no Canadian, Mexican or US border agent has ever asked me and all the pax in my car, including children to state their names?

We have never had that requirement enforced on ferry, bus or train crossing of borders, either.

That's aside from the fact that asking a child to state his/her name on a domestic itinerary proves nothing - they are not required to provide an ID. Their name only has to match the name given on the BP. A child traveling internationally does have to provide matching ID, but again, unless TSA is doing actual computer checks on the spot, it's possible that the kid is being taken out of the country in violation of a court order - under his/her own name.

In short, it's a one-in-a-million long shot that merely distracts further from the real mission.