You'll find that the UK and the Irish government share border information.
Well you are persistent but still incorrect.
Did you read that link?
This initiative is aimed at putting in place standard entry requirements and enhanced electronic border systems;
Meaning that there are none at the moment and never have been any.
In a statement the governments said the deal would prevent abuses of the Common Travel Area arrangement while protecting its benefits to trade and tourism, and will target what are termed ''high-risk'' countries for bogus asylum claims.
Polish people are not illegal in Ireland or Britain, meaning that they can wander around as they like.
Now you were wrong and are still wrong.
I would stop grasping at straws if I were you