Now that in the real world we're embarking on a single Europe wide compulsory (no matter what the govt. say) ID scheme with biometrics I find it interesting to compare to the world of shadowrun.
One specific feature caught my eye in a piece I read a few weeks ago - that of actually cross checking the database for duplicated records. Effectively this would mean that once an iris scan has been used for ID for a person then the same iris could not be used again. This seems like a quite good idea for maintaining the integrity of the database and preventing fraud.
In the real world this is going to make identity theft an order of magnitude more difficult than would otherwise be the case and prevent people from maintaining more than one identity.
Does the SR SIN database perform anything similar? - judging by the number of runners with multiple fake IDs I'd guess not...
On that note - what are the (in game) impications of multiple IDs? I can imagine a runner getting arrested. The LS Officer takes the runner back and they ID him...
"Says here that you're Mr John Stevens, is that correct, boy?"
"Sarge! There's a second result on the search"