I don't know for sure. But I would relish a law that says families with children cannot live in such pedophile playgrounds and landlords cannot rent o them.
Chris is right. I'm not sure having these buggers in one location is that helpful. many of them have cars. It's more about making life very difficult for them so that others do not want to follow their paths. It probably doesn't work - it probably doesn't deter one of these creatures. But I'm okay with having them as uncomfortable as possible, and in an easy location for police to go to, parole agents to visits, so they don't have to drive all over town. I just don't think families should be anywhere near them.
But let's be somewhat reasonable with these laws. A 20 year old who has sex with a 17 year old girlfriend is not the same as grampa molesting a little kid. Such a guy should not be subject to the same restrictions.
BBM. Let me preface this post by saying I am a former licensed realtor and let my license lapse after becoming a single parent due to the weekend and evening hours.
I don't think legally a law such as that can be implemented. I think once someone has served their time, they've served their time just like they have for any crime. Sex offender registries, crime registries are available for those who chose to utilize them.
We can only go so far to protect people. It is up to the buyer or renter to do their own homework on neighborhoods, crime statistics etc.
ETA: It is against federal fair housing laws to discriminate against families with children/familial status. A landlord or owner refusing to sell to or rent to a family with children would find themselves facing a law suit. Except in communities designated 55 and over only.