Since when are passport numbers supposed to be sensitive information? This isn't something you could use for identity fraud in any normal circumstances.
Maybe? But also maybe not really?
Passport numbers change very frequently, nobody uses them to identify people.
As a perpetual foreigner I've never had to use my passport number for identification.
>passport S/Ns are being used as part of identification procedures.
Where?
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.