These red-light districts waned in part because the Internet became the preferred place to pick up a prostitute.
Even the most down-and-out sex worker now advertises on Craigslist (or did until recently), as well as on dating sites and in online chat forums.
Peter Moskos's recent book, "Cop in the Hood: My Year Policing Baltimore's Eastern District," describes how police often play counselor to sex workers, drug dealers and a host of other illegal moneymakers.
In my own work, I've found that cops are among the most empathetic and helpful people sex workers meet on the job.
Of course, selling sex is an old business -- most say the oldest.
I found that 80 percent of the men who contacted women via Craigslist in New York never consummated their exchange with a meeting.As a result, pimps' role in the sex economy has been diminished.In addition, the online trade has helped bring the sex business indoors, with johns and prostitutes increasingly meeting up in bars, in hotels, in their own homes or in apartments rented by groups of sex workers.Last weekend, Craigslist, the popular provider of Internet classified advertising, halted publication of its "adult services" section.The move followed criticism from law enforcement officials across the country who have accused the site of facilitating prostitution on a massive scale.