Doing it wrong

Three tenuously-related pieces of news have caught my eye recently.

Firstly: NDNAD, the UK's National DNA Database, run by the Forensic Science Service under contract to the Home Office contains DNA "fingerprints" for lots of folk — 5.2% of the population as of 2005, or 3.1 million people. Some of them are criminals; some of them are clearly innocent, but were either charged with a crime and subsequently found not guilty, or had the misfortune to be detained but not subsequently charged (that is: