Originally Posted by
AaravM
Given how many passports they have to check, it's logical to think that are not looking at every detail in your book. They have scanner these days that scan reads the machine code text with your name, dob, pob, cItizenship, passport number and validity.
Yeah, but... I think the chances are very very great that each immigration agency (in any country, US, UK, India...) has software that pulls in a great deal of information on you from various other databases of immigration and other matters. When they scan your passport, it's not just your DOB and passport number and such that they can see on screen - very likely they can see your full profile with all exits/entries on record, even those connected to other passports and so on, and they can pull in additional information if needed too.