[cr0sh]

> You people treat it as a secret while it isn't.

It isn't now. But it used to be meant that way. I'm not sure what or how it started.

But old SSN cards had a line printed on them (on back, IIRC - probably not the best place) which read something like "For Social Security (or maybe IRS?) Use Only - Do Not Divulge".

That line has quietly disappeared (sometime before I was born - my Dad and my Mom's SSN cards had the line, but mine doesn't). Likely because the cat got outta the bag, and they realized it no longer mattered.

I imagine that it probably started with some company or other government agency deciding to use it without authorization of the SSN/IRS - and people went along with it because "it's the government, we can trust them", or some such malarky. Furthermore, most people probably never read the back of their card to find out that they weren't supposed to give that number out to just anyone, and of course no one thought of the potential implications to which that number could be applied.

This of course applies to any form of ID using a unique identifier: Bad actors in the system can easily exploit it - and when you are identified by a number, that number (and everything attached to it) is you - regardless of whether it really is or isn't.

Of course - all of this and more was covered in the book "Database Nation" - which was widely ignored.

[catbird]

I think the line you're referring to actually read "For social security and tax purposes - not for identification." As it was explained to me, it meant that the card itself was not a proof of identity, as opposed to something like a drivers license that had a picture and other identifying info.

https://en.wikipedia.org/wiki/Identity_documents_in_the_Unit...

[Nomentatus]

In many countries it was originally illegal to ask for an SSN(equivalent) as identification; the line suggests that was originally true in the U.S. as well.