You are not legaly obligued to provide pictures or fingerprints in the US? Over here, we must have a personal ID which has photo and fingerprint, and you cannot do anything without that ID. When getting into the US, brazillians (and some other also "non apreciated" nationalities) must take two photos and taken all their fingerprints out (digitally) before getting in. And I don't think that's intrusive at all, I think it's practical. I mean, it's not all crime related: what if I go to the US and get into an accident and lose my memory, get into a coma or die, and my documents are lost, how will they know it's me? If I had to give DNA samples to the government identify me, I would, no problems.