Thanks for posting the journal source. I have not personally studied anything in abnormal psychology or criminal psychology in several years so I am not sure where current research is. I definitely want to check this article out.
As far as treatment goes I would never argue against it. Even if only helped 1 in 100 it would be worth it. As to why treatment works that depends on a lot of factors. What does the treatment entail? What are they learning? I would imagine they are undergoing a more cognitive-behavioral approach than say talk therapy and social dynamic type stuff (although that might be beneficial to some of them too). If so then I would like to know just what they are learning in terms of response to temptation as well as how to avoid temptation. Like I said, many of those who go through treatment learn to become reclusive. They often do so because it is easier to avoid the thoughts and feelings that come up with certain types of encounters thus it is easier to prevent them by avoiding certain situations to begin with. There is also the social stigma that accompanies being a sexual offender which leaves many of them with nowhere to go and nothing to do and thus isolation again. It's like a double whammy.

As far as public urination versus actual sexual offense such as molestation and rape goes you are correct. I didn't clarify that when I commented on registering. I was thinking mainly of things like rape and molestation. I am one who believes things like public urination does not belong on the sexual offender lists. But the inappropriate addition of such cases doesn't negate my point either. Sexual predators are registered and tracked for a reason, because they repeat.

As far as the ethics issue goes, I don't have an answer and I really don't know what should be done. I think it unethical to mete out something like life in prison to a first time offender but I don't know what is the appropriate and effective punishment.