Every time you go to a new doctor or dentist and they give you a clipboard brimming with documents to fill out and sign, notice how they always ask for your Social Security number? Do you dutifully give it up? Did you ever wonder if they really need it?
I once asked a doctor why he wanted it. His response: “I don’t really know. I guess it’s because we’ve always asked for it.” (In actuality, most doctors ask in case your insurance doesn’t pay the entire invoice and/or to fill out a death certificate if you die. Offer a next of kin who knows the number instead, and your phone number for billing issues.)