i had a mate who was very irresponsible with his car, it was a cheap car and he would leave the windows down overnight, leave it unlocked and even with the keys i the ignition barrel sometimes.... the one night he locked it up it got stolen.

Moral of the story is that sometimes giving things away or if a task is too simple people wont even bother trying, if they have a bit more of a challenge it becomes desirable.... there is some psych backing to this theory as well ;) the hooman mind, lolz.