The European Union this week is starting to roll out a new Entry and Exit System (EES). What it will do is register all non-EU nationals who are entering for a short stay. It allows each of the states individually and in co-operation to monitor the movements of people when they cross the external borders of any of the countries using the system.
This would appear to be an excellent means of detecting people who might overstay their welcome for whatever reason and potentially help to identify those who are abusing the free travel system for criminal or illegal immigration purposes including human trafficking.