Something similar is done in Denmark. So guy a with dual citizenship goes to Syria to fight, his Danish citizenship gets revoked by administrative means. How d

Something similar is done in Denmark. So guy a with dual citizenship goes to Syria to fight, his Danish citizenship gets revoked by administrative means. How does the authorities know that particular guy was in Syria? Will they let the guy know? In broad terms yes, in details probably not. He can come back to DK and have his day in court and jail, if he wants to find out more. Sounds harsh, and I am not sure I agree with it. But that is the way this type of legislation works.