Why US Social Security Cards Have Never Been a Secure Form of Official Identification
The very knowledgeable CGP Grey explains the origins, history and uses of the US Social Security Card. Grey made note of the fact that, while the card is often used as a form of official identification, it was never meant to be used as such and so was never made secure.
The desire of Americans to not have a national identity card led somewhat inevitably to the nearest thing available being used as a substitute. And it ended up being worse because the social security number was never designed to be used this way in the long, long ago and you can tell because it has no security built into it.