It is the point of exist -. infact many airports now have these portable screening vans and luggage from all these places are screened to 100% before it is put onto the lugage belts for pick up and if they have something suspisious they will check who takes pocession for the piece of luggage and then invite this person to customs inspection where everything is rescreened in your precense and its jail if they find something. It just depends on where you come from. Amsterdam is another one of those places they like to check well because of the "coffee shops"