Don't all sorts of person-related details come in handy to stage a social engineering hack? Maybe a caller could demonstrate legitimacy by coughing up a passport number. At this point, it may impress me more than someone having found my SSN (_love you for that, Equifax_). Yet, SSN is still by many institutions considered something that should be stored in the vault.
I don't know if you are joking or I need to break it to you that in most cases passports are the de facto identification for foreigners and passport S/Ns are being used as part of identification procedures.
They change frequently? My passport is the longest-lifetime form of ID I'm offered, the absurdity of using Social Security Number as an ID aside. Most passports last for 5-10 years in my experience, and I'm not sure the number changes when you renew it.
> I'm not sure the number changes when you renew it.
Of course it does. Numbers used to identify people generally don't. Passport number identifies the individual document, mostly so it can be checked against INTERPOL's SLTD database.
