A court ruling in New York last week about where sex offenders may live has rekindled a debate over whether such laws really work to protect children.

New York's Court of Appeals ruled that only the state has the power to tell offenders where they can and cannot reside, and generally only while they are on parole or supervised release.

The ruling effectively struck down more than 130 local laws across the state. Many of the laws went further than state law by placing restrictions on where offenders can live for the rest of their lives.

Some experts argue such residency restrictions may not provide the protection for children the laws envision.

Jill S. Levenson, who teaches social work at Barry University in Florida, says there have been numerous studies that show there is no relationship between where a sex offender lives and the likelihood to re-offend.