. . . deals with the labels on your cases, especially at airports. If your name and address is visible or easily accessible, you might just return to find stuff missing when you return.
We don't have a formal neighbourhood watch scheme, but the people in our road tend to keep an eye out for anything untoward. There was a pick-up truck cruising around for a day or so a couple of years ago, and suddenly there was somehow a sprinkling of people who found the need to take the air, stretch their legs, or do some gardening out front. I suspect the driver had the uncomfortable feeling that somebody was watching . . .