Originally Posted by
Doc Savage
There are readers for your implanted microchip at all public transit stations.
They know.
And then there are the security agents who follow all non-EU passport holders around. They cunningly dress as national stereotypes to avoid arousing suspicion (though this is a bit of a problem for Luxemburg as they don't have a national stereotype). Did the OP spot the characters from "Tintin" behind him/her in Belgium?