What does"the man" know about you from your passport?
 

I recently did some work with a co that sells systems to immigration depts and potential employers like health and the cops, to vet people. Most of the bigger or more security conscious countries use them. Given the nature of their business they are given extrordinary access to databases by a lot of governments. They scan your passport. Firstly there are more than a dozen ways of spotting fakes, the machines are very good, and if anything is questionable, a helpdesk of their experts is sent a set of visible, uv, ir and other scans plus the data chip contents to look at, in about 5 seconds. Once a passport is blacklisted, or used fraudulently, its effectively blocked.

Once they can recognise your passport no they can via your countries social security or revenue service get your address and other id. They will compare any held photos with these people. They can use that to do financial checks, criminal history, etc etc there are even potential terrorist db's from several countries and undesirables and diplomatic lists. The countries are happy to share for this worthwhile cause of course.

All this is in seconds, ive seen it. Some searches cost a few pennies, its up to the system user what they choose to search and what to do with the answer, but dont dismiss these systems, if you are an honest upstanding person, they know far too much about your global "fingerprint." I think sometimes this is why people are picked up on landing. The leaving country flags the document which is then unusable later. Of course if you are a refugee with no passport....