Employing virtually the same logic as proponents of the decriminalization of drugs (i.e. smart people), advocates for sex workers in California recently filed a federal lawsuit which aims to legalize prostitution in the state. The lawsuit calls the current status of Californian prostitution (very illegal) an "unconstitutional violation of equal protection and free speech rights," a claim which actually makes a great deal of sense.
The lawyer representing the plaintiffs (namely advocacy group Erotic Service Providers Legal, Education and Research Project alongside three potential legal prostitutes and a disabled man vocalizing his status as a prospective customer) says that the current climate of the underground industry of prostitution places sex workers at an increased risk of abuse due to their obvious avoidance of law enforcement officials.
Just as Nixon's ludicrous War on Drugs has become an embarrassing stain on American policy, the harm and violence caused by criminalizing prostitution is far worse than the alternative.