I've always been asked to wait around while the run the bag through the machine, but have found that if I use a plastic case, they usually don't need me to open the case. When they have needed to open the case (I flew for years with a metal case and always had to open it), they asked for the key and opened it in my view and then re-locked and handed me back the keys.
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I pray that my son, when he is 60, and your son, when he is 60...will live in a world from which the great ugliness that has scarred our century has passed. Enjoying their freedoms, they will be grateful that, at the threatened nightfall, the blood of their fathers ran strong.