The law is designed to keep sex offenders away from children by monitoring how close they live to schools, parks and other spots where kids gather. But critics say it unfairly subjects homeless offenders to a life sentence if they fail to register a home address.

The Georgia Supreme Court's 6-1 decision Monday found the law's registration requirements were "unconstitutionally vague." The opinion also held that homeless offenders are not exempt from the statute, and suggested special reporting requirements for the homeless.

The case involves William James Santos, a homeless man and convicted sex offender who was kicked out of a Gainesville homeless shelter in July 2006 and was arrested three months later on charges he failed to register with Georgia's sex offender list.