Credit agencies use your SSN to identify you. The banks use your SSN to identify you. The IRS uses your SSN to identify you. The medical system uses your SSN to identify you. Countless other agencies use your SSN to identify you. This isn't so much a problem except that they also use it as an authentication token which is ridiculous.

To authenticate yourself over the phone, all you need to recite is:

* Name

* DOB

* SSN

* Address

* Mother's maiden name

None of this is private. From a privacy perspective, to think this is secure information is ridiculous on its face. Identity fraud is only limited by a criminal's risk tolerance and various companys' fraud prevention measures.