Coming in rather late to the game as far as this whole conversation goes, but if the above is true, why would you then ask for someone else's SSN?
I always do that when some one asks me personal info.
You now what I say to the begger approaching the car, knowing he's going to ask for spare change, I always get the jump on him and say, "hey, you got any spare change"? The begger usually goes on his way at that point, with a confused look on his face.