Which borders exactly?
All of them; especially towards undocumented aliens.
As long as people don't get shot dead attending a rock concert i really don't care if they hate us.They can hate us all they want from behind a fence,just like a chained rabid dog.
The moment they take their 'hate' and apply it into violent action, that is the moment the thin red line is crossed. Then it is right for Europe to retaliate in a responsible manner.