My wife and I were discussing the "Baby on Board" stickers while driving the other night, and she raised an interesting point: could it make the people driving the car with the sticker more of a target because the hands of someone with a baby are inherently more "full" than someone without? Also, a parent is more likely to be concerned with the child than a material possession (i.e. keeping the thief from getting the car, purse, etc.). I had never really thought about it, but it does bring up an interesting point.