Fingerprints are probably a good comparison, the factors used AIUI mean about 1:1M chance of a random match (that's from a few years back, maybe they changed ho

Fingerprints are probably a good comparison, the factors used AIUI mean about 1:1M chance of a random match (that's from a few years back, maybe they changed how they gather/process/match fingerprints). That's not great, but people perceive it as "fingerprints are unique".