I have noticed over the last ten years since I started to put zip ties on to secure my suitcase from being easily unzipped, that nine out of ten times it as been opened up. The reason that I started doing this is because I noticed that my bags have been gone through. And yes I understand that they can be gone through in customs before you retrive them. So I never leave anything valuable in my suitcase,always carry them in my backpack. It has been kind of a game now, this year I zip tied and used duct taped to tape my suitcase shut and it did not get opened.