Well, these laws are an attempt to get around the belated realization that a five year sentence and release with minimal supervision wasn't dealing with the hazards these pervs represent to society. If New Jersey had mandated life sentences retroactively after these pervs were convicted, as opposed to a registry, SCOTUS would have overturned it - I guess SCOTUS was winking at this law, deciding that it was not an excessive burden on the invididual and therefore they were willing to overlook ex post facto considerations. But the states need to make some serious changes to sentences for these guys - mandate lifetime probation, treatment, and also a life sentence as an option - or, just let my wife have five mintues alone with them, that would work as well.
Because that's the court system. They serve their sentences and they are let out. However, I understand people who commit these types of crimes can never be rehabilitated. It's like an addiction for them. So the chances of them committing another crime are great.
Not to mention - where would we keep them? If you go to the FL Dept. of Law Enforcement web site - www.FDLE.gov, and go to the sexual offenders registry, you will see hundreds (if not thousands) of offenders listed.
This is a great tool if you're looking for a house in another town. But then, what do you do when you find out that one lives in your neighborhood? Certainly you would shield your kids from them. Then what? Cross the street if you see them walking towards you?