Experts say it is an issue illustrated by a New Mexico case involving a retired professor and a former college administrator who were accused in what police described as an extensive multistate, online prostitution ring.

Investigators alleged the men operated a website that recruited prostitutes and promoted prostitution. But the two were cleared after a judge ruled in June that state law says the website didn't constitute a "house of prostitution."

Legal experts say the problem stemmed from authorities trying to apply old prostitution laws in a high-tech world — and it happens in many states. Further, the National Conference of State Legislatures says state legislatures aren't actively working to update prostitution laws.