Which is a problem of its own, since they're effectively usernames.
Secure usernames that have no corresponding password is already an oxymoron; that's what credit card numbers used to be, hence the introduction of the CVV, 3DSecure and so on; but at least a credit card can be blocked with relative ease. But SSNs are secure unchangeable usernames, which makes even less sense.
Do any countries other than the US have such an abomination, where you can figure out the SSN of someone and ruin their life?
Secure usernames that have no corresponding password is already an oxymoron; that's what credit card numbers used to be, hence the introduction of the CVV, 3DSecure and so on; but at least a credit card can be blocked with relative ease. But SSNs are secure unchangeable usernames, which makes even less sense.
Do any countries other than the US have such an abomination, where you can figure out the SSN of someone and ruin their life?