Originally Posted by corporate-wage-slave

I would say the chances are that this is still an accident, someone picked up a bag they thought was their own bag. It doesn't follow that there would be a similar bag left behind, though I have seen that happen. Among the other scenarios - there is a family group with lots of bags, they all pick up what they think is the cohort's set of bags and only when they get to (e.g.) the hotel they realise someone picked up the wrong bag. Now because they may feel they were being stupid here, they may not contact anyone about it. Other people would have a different mindset and urgently find the contact details - so even in hand luggage it's worth having contact details in the bag, though not visible on the outside. Equally some people are in a bit of a panic / daze when arriving, not concentrating, and simply pick up a bag that looks a bit similar to one familiar to them, and only engage brain later. Realistically if the bag had been moved by cabin crew to one compartment, someone else, trying to get their items out, may have moved it to another compartment, or left it on the floor somewhere. Yes, theft does happen in some parts of the world, but I wouldn't attribute this one necessarily to malice. It's not a worthwhile chain of thought anyway - the bag has gone missing and the owner wants it back.