Years ago flying TWA from Vienna, Austria, my wife and I were flying with locked checked luggage. Apparently security x-rayed the bag after check-in but prior to loading it onto the airplane and found something suspicious. My wife (whose nametag was on the bag) was paged to come unlock the bag so it could be searched. Of course she had just gone to the ladies room and they wouldn't tell me why she was being paged. Eventually when she came out, they escorted us out to a private area which held the bag and asked us to open it. It must have taken us at least five more minutes to figure out which one of us had the keys and where we had packed them in our carry-on luggage. We were lucky that they waited for us during all of this and just didn't send the plane on without us. After this experience, I can understand (as much as I HATE the idea) why the TSA wants the checked luggage unlocked. In the mean time, I just resolve to fly only with carry-on luggage to the extent possible.