And the public part of the registry may be a failure, being a primary cause for under-reporting offenses, because who would want to report their brother or sister for fondling their kid, only to have that stain on their entire family, forever?  An effective registry of sorts had existed, long before, as the police knew who they were, and kept a mental track of the ones who were dangerous to more than their own family.  The families kept track of their own.  As you were growing up, did you ever wonder why "Uncle (or Auntie) (or Cousin) So and So" never showed up for holidays and stuff?  Some other unintended consequences of the public registry are:  The serial offenders are suddenly aware of just how many of them there are, and where, and they could possibly organize, just like the LGBT's did.  The Kiddy-Porn industry now has a nation-wide list of potential customers.  And several foreign countries have banned adoptions by Americans, as, in their eyes, we look like a nation of perverts.