Do "child safety zones" stop abuse?

NYTimes    Orange County finds itself at the enter of a new wave of laws restricting the movement of sex offenders. The county government and a dozen cities here have banned sex offenders from even setting foot in public parks, on beaches and at harbors, rendering almost half the parks in Orange County closed to them. Ten more cities are considering similar legislation. 

And Orange County is far from alone. In recent years, communities around the country have gone beyond regulating where sex offenders can live and begun banning them outright from a growing list of public places.[...]

The proliferation of such restrictions reflects the continued concerns of parents and lawmakers about potential recidivism among sex offenders. But it has also increasingly raised questions about their effectiveness, as well as their fairness. 

Opponents have dismissed “child safety zones” as unenforceable, saying they are designed to make politicians look tough on crime and drive sex offenders from the area, not make children safer.