I think Pat was implying that they may not announce that they were looking for a terrorist (or other person) by using the checkpoints. Instead use a public safety excuse for the stops.. it won't cuase panic or tip anyone off.
I suppose it's possible and even likely to have been used for both purposes.

Up in these parts they usually just announce they are having more cops on the road watching for drunk drivers, especially on holidays, etc.

Personally I consider Canadians as Americans. I like to picture both countries as 'related' in many common needs.
They are not US citizens, much as I am not a Canadian citizen. As John is well aware, citizens from both countries intermingle quite a bit in this area. My daughter is dating a Canadian who has moved to the US within the last 5 years or so. His parents split and they each live in their own country now. All divorces should end so resolutely!

Make your sound your own!
.. I do not work here, but the benefits are still awesome