There could be another possible benefit to doing this.

I am reminded of the couple in CA who were lost in rough terrain, and stumbled across the campsite of a man presumed dead. His backpack contained extra clothing and matches, things that allowed them to survive and start a signal fire.

http://www.msnbc.msn.com/id/12737512/

In the Alaskan and Canadian bush, it was long a given that you didn't lock your cabin door, just in case someone needed shelter.

Of course, sometimes the life you save is your own.

Sue