"It's definitely not a big deal for most people who already gave their credit cards with name and address to add the *last four digits of their SS#*. This information is routinely asked for -- and given -- by these self-same credit-card companies and banks each time you call for information about your account."

You do of course realize that with my cc# and the last four digits of my social, anyone can call my credit card company's 24-hour customer service line, pretend to be me, retrieve balance, next and last payment info, and available credit? With one more tiny piece of information, which I "routinely give" to the banks, namely my mother's maiden name, anyone can initiate a balance transfer, reverse a charge, change my billing address and phone number, or close the account?

It is far from harmless.