I'm older than most of you. Do you know what my SS card says? "For Social Security and Tax Purposes. Not for Identification."
It doesn't say that, anymore, does it? And don't try to tell me that it doesn't stay in the system, JesseTrue. I was at MayCo with a friend, and she handed the clerk her MayCo credit card, and the clerk asked for her SS number. Now, if she needed the SS number, what would she be MATCHING IT TO, if what you say is true?
All someone needs for identity theft is your SS # and your birth date. To pat you on your little fuzzy head, clerks 'just' ask you for the last four digits. And that's a con.
The first 3 digits of your SS # are the Area Number -- it indicates the geographical region where you were when you applied for the number (or when your parent applied for it for you). While it isn't always where you were born or grew up, it usually is. And it's pretty easy to find out where.
The next 2 numbers is the Group Number, and refers to the state you were living in at the time of application.
The third set of 4 numbers is your serial number, which is assigned at random, consecutively, in order of application. My last 4 numbers and my two sisters' numbers are consecutive; the next one was given to the next applicant in our state.
The most difficult number to apply to you is the last four digits, because it isn't based on anything more than where you were in the SS line for a card/number. If an identity thief (say, the clerk's boyfriend) gets that, all he needs after that is where you were born, which is easy enough to find, and when, also easy -- just ask Whitepages for a good guess.
The same friend I was with at MayCo was once chatting with a stranger, when he said, "You sure remind me of a woman I used to know in _____...... What was your mother's maiden name?" She actually opened her mouth to tell him (it's quite unusual), when something nudged her, and she was quick enough to hesitate for just a moment, and said 'Smith'.
Sure, many companies know your SS #, but you don't have to give it out like a street-corner hooker giving out her phone number.