Unfortunately, about 40 years ago, I was employed by a corporation in a capacity that required them to file documents identifying me by SSN to state regulators in several states, such documents being available for the public to inspect, not withstanding that I still have my original Social Security card, which says thereon quite clearly "Not for Identification."

The SSN does not have the attributes of a good permanent identifier of a unique person. If you get an SSN with three consecutive 6's in it, you can get it changed to another one not containing that string. Worse yet, the Social Security Administration has reserved the right to reuse the SSN's of persons deceased (IDK if they can or might do that without giving further notice). Furthermore, the US government talks as if there are two completely different kinds of numbers that each use 9 digits, and that they might overlap, ie use the same numbers for different entities; one being SSN's and ITINS, and the other EINS. However, the practice of the IRS and SSA has been to do their best to make sure that they do not overlap, at which the results have been as good as can be expected, but not perfect.

As many games have been lost by one card too many as by one card too few.