Regarding the "end the prisons" concept:
We can all agree that there are some folks who should probably be locked up due to either the heinous nature of their crimes or their proclivity to commit them: pedophiles, serial killers, others I'm too tired to name right now. However, there are other ways to punish, deter, and rehabilitate folks who break certain laws, without incarcerating them.
Here are certain facts that you might not hear much about, but since I've been both a prosecutor and a defender, I think I can speak about them semi-intelligently at least:
1. For certain segments of the population, "Doing Time" is no longer something to be feared or avoided, but in fact has become a rite of passage or sign of manhood, giving the individual street cred.
2. Prisons are institutes of higher education on how to become a better criminal. Guess what the inmates do: They spend much time passing secrets, tactics, and tips of the trade back and forth.
3. If you stop incarcerating folks for victimless crimes, i.e., vices (drug use, prostitution, etc.), your prison population would plummet.
4. Many of the theories of "lock 'em up" have their basis in the assumption that there are no other valid ways to punish, deter, or rehabilitate. In other words, it's like the dad who always administers an asswhipping instead of taking away the car or the TV; he cannot think outside the box.
Until we start thinking of law and order more in terms of intelligently creating an unwillingness in the general population to commit certain acts that we call "crimes" instead of thinking of it in terms of moral outrage that someone would DARE to break the law, the system will remain broken.