Law of Unintended Consequences
FD: i'm a lifelong geek, with 20 years of professional experience in IT, mostly support and infrastructure, from POS up to datacenter design and implementation.
i don't recall who it was that said that society only changes due to the impact of technology, but i seem to remember that many people were outraged, and debunked the idea immediately.
this seems like a fine example of that concept.
governments are certainly incompetent at collecting data, but they are even less competent at validating, synchronizing and securing data. this turns your travel experience into an interesting game of chance: if data in Australia (for example) says that your name matches a "person of interest", will you wind up at Gitmo the next time you try to visit New York? once bad or misleading data spreads to other databases through "sharing", who will correct the errors? if someone fixes the mistake, will it be fixed in other "sharing" countries?
the US has an arrest database (the NCIC), where every arrest is noted, even if the arrest is by mistake, or never results in a conviction. the data is accessible to private parties, which means that one arrest can result in being blacklisted for life, never to find a high-paying job again (background checks frequently include arrest records). once the data makes its way to information brokers, it never dies and never gets fixed, as "what goes to the internet, stays on the internet". even if the record in the NCIC is expunged (which they almost never are), enough other databases have duplicates that it makes no difference.
maybe when this hurts enough innocent people, the public will wake up and turn against it. presently, most of the US population is apathetic, ignorant, and determined to remain so. there may be outrage elsewhere, but there is none here.
good luck with that "sharing" thing.