A thought experiment
As DNA is based on cell samples, the more thoughtful (for lack of a better word) "criminal" would probably think ahead a little. There are two methods for negating, or nullifying DNA collection. One is by not leaving any DNA to collect, and the other is by contaminating the (again, for lack of a better word) "crime" site with others DNA.
It won't be long (possibly) before stealing trash from such places as (e.g.) hairdressers, or clinics becomes commonplace. Think about it for a moment...
>Take a bunch of DNA (human or otherwise) belonging to others, with you on your "CRIME".
>Strew said DNA around, thus making any sort of DNA collection/examination prohibitively expensive, not to mention slow & frustrating for the nazis^H^H^H^H^Hpolice:
>Ensure that you wear generic, throwaway clothes.
>Wear latex gloves (assuming that they don't become a restricted item. If so, find alternatives).
>Gel your hair inside a (generic) hat (with generic gel). Hell, a bit of vaseline(tm) over your exposed skin could be useful.
>Don't repeat the same offenses. If they (the rozzers) are annoyed enough, they could do a statistical analysis on the 100's of DNA samples obtained from the "CRIME SCENE" and possibly try to finger you that way.
... There is a lot to be said for no-name branded clothing ... It's huge dispersal within a population, for one.
All in all, if everybody who took to crime followed these ideas, they would probably be doing the rest the UK (& world... eventually) population a great service.
[posted anonymously & from another country for black helicopter-style reasons]
Remember, they govern by the consent of the governed. If enough people say enough, then it should mean ENOUGH!