>The problem with this approach is that its counterproductive, as many prisons act as graduate schools in crime.

As are the streets.

In this model of 'removal', I'd say that the main point of a prison is to take a more crime prone demographic (by that I mean age, gender, ethnicity, location, wealth...the whole ball of wax) off the street until they are older and less likely to do things that the straights don't like.

In the long run, I would expect for universal surveillance (and the increased ability to parse data we are seeing) to be the main driving force in social control rather than mere warehousing.