here in holland, there are certain area's with a total ban on knife's. That includeds knife's deep in you luggage. The police do preventive searching in these area's ( and sometimes others )so they will find it. But most of holland the rules aren't very strickt, BUT one of the laws says that if you got any object that can only be used to injure other, than he can take legal action against you. Since thats a opinion, you might get in to trouble if you don;t have a good reason.