" in 2 months of operation, with up to umpteen thousand searches per day, Interpol have arrested precisely *one* suspect? "
*If* that's true, that's actually pretty good. Hundreds of arrests would indicate either a high false positive rate (although TBH we know nothing about how many people were wrongly stopped before this 1 arrest was made), or that it was being used as a trawl net for trivial offences. Also good to note that this is actually a good way of implementing biometrics. Comparing a live photo to a "whole population" photo database is bound to give dozens of positive matches. Comparing to a select group of 'Interpol's most wanted' (ie thousands rather than hundreds of millions) is far less likely to flag false positives.