Was it really that difficult?
When you travel to the USA for example you need a Visa and you fill out a I94 form on board one part of which is surrendered at Immigration.
Why can't someone design a similar system here to control our borders?
We need to know how many came in and how many left. The difference between the two numbers is the number of overstayers you would imagine.
What would you do with that information?
It's not too difficult.
My paper.li papers