Padlocks protect you from baggage handlers getting a little on the side while on the job. If a baggage handler slices your bag open with a knife, that&#x27;s going to be noticed quickly, and the odds of being caught are high. If the bag is unlocked and he can merely unzip it, pocket something valuable, and replace it, then that may not be discovered for many hours or even days, and the odds of being caught are much lower.<p>Obviously they don&#x27;t protect you from someone who simply steals your entire bag, to open it at leisure away from the airport. But something doesn&#x27;t have to protect against <i>every</i> conceivable threat in order to be useful.<p>Locks on your luggage is like locks on your front door. A lock on a normal house door is easily defeated with a crow bar or a strong leg. But they&#x27;re still useful to keep out people who are willing to use the door knob but not actually break down the door.