Today we have checkpoints usually on rather virtual lines drawn by military conflict. In the past only every settlement had such check points.
Check points always create a barrier and limit movement. If 20 million humans travelling every year through the Eurotunnel and that tunnel has check points on each side in Paris and London than Paris and London can check who is visting town.
If France had in the past up to 70 million visitors counted by traspassing a line in the woods, you have fuck no idea where they went.
As useless in plain English are national boarders.
Look at France and whom you want to find on its boarders. Most likely customs is looking for drug smugglers and bandits looking for loot, beside checking for import tax vioalations. Paris.
All markets are local and so are those for drugs and theft victims or goods worth avoding taxes, but by creating checkpoints to overwatch 70 million humans you both help criminals to sneak through and hurrass everyone by being checked and having to interrupt its right of movement.
The easiest way to find a Fenthanyl smuggler is by being in Kensington Philly and cheking up on the users, to the dealer, to the gang and smuggler, but the technology and humans needed to so so are bussy cheking car rides on a high way.....something you might get shot for in remote Texas I guess all rightously...while some can create incredible databases of finger and handprints....that might create an Eigentor one day
