PROVIDENCE -- Rhode Island has a long tradition of going its own way. Founded by religious outcasts, it was the last of the original 13 colonies to join the union and the state mascot, which sits atop the State House, is a bronze figure named the "Independent Man."

But there is one distinction about which many in the state aren't proud: Due to a legal loophole, prostitution is legal in Rhode Island as long as it happens indoors.

Now,...