I, for one, would never submit to fingerprinting or other types of profiling while doing nothing more than conducting my daily business. It may be harmless at the moment to give over such information, but I worry for the future.
IE: While travelling I'm fingerprinted, photographed and questioned at length purely because I am of some ethnic group or meet some other criteria. Jump ahead a few years and I'm attending a peaceful protest against police brutality or globalization or whatever and I'm photographed again, secretly, by police inteligence (and they DO photograph people at protests, trust me). This photo gets fed into a database and they find a match with my travel entry. Now they have my name, all my personal info, fingerprints, etc... and they now know I'm a bit of a dissident/activist. Repeat the cycle of attendiing and being photographed at so-called "radical" (but peaceful) events and sooner or later I end up in a political dissidents file. Then some maniac, or maniacs, decide to go and blow up a building again or commit some other atrocity and BANG, I'm in a federal prision with no warrant, no charges, no bail, no lawyer, no consular services, indefinitely. All because I matched some profile when I "innocently", having nothing to hide, submitted to questioning and fingerprinting.
Think this is a bit far-fetched? Tell that to the hundreds still in prisons in the US without charges or trials for over a year now....