Gone are the days of the nameless, faceless "john." Men who buy sex are now likely to end up with their faces splashed across the Internet or the morning newspaper.

A Maine tourist town shaken up by authorities' promises to reveal the identities of dozens of clients of a fitness instructor accused of prostitution is just the latest place to enlist public shaming as a preventive measure.

Fresno, Calif., sponsors a website called "Operation Reveal" that features mug shots of suspected johns, while Oklahoma City has the vigilante-style "JohnTV." In Arlington, Texas, a highway billboard declares "This could be you" under the picture of four suspects.

In Maine, the small-town scandal has literally put Kennebunk on the map - it's now part of a database tracking more than 870 municipalities that have launched initiatives targeting men who hire prostitutes.

Interviews and surveys of officers at 200 police departments nationwide since 2008 found most consider targeting customers the best way to curb prostitution, because they fear publicity about the charges more than fines or even jail time. It continues a long-developing trend away from prosecuting the "supply" side - the prostitutes themselves - and targeting the demand.

"What they usually ask is, 'Is my wife going to find out? Is my boss going to find out? Is my name going to be in the paper?"' said Michael Shively, who conducted the study funded by the National Institute of Justice.

In the case that has embroiled the coastal town of Kennebunk, 29-year-old Alexis Wright is accused of operating a prostitution business out of her Zumba studio, secretly videotaping her encounters and keeping meticulous records of her clients.

Police plan to release more than 100 names little by little over the next several weeks. The warning has set off a flurry of rumors among residents who say they've heard the list might include lawyers, doctors, law enforcement officials and a television personality.

A lawyer for two men believed to be on the list asked a judge to prevent the release of the names. The judge declined, but the lawyer has appealed to the state's top court, which won't rule until at least Monday.

Law enforcers and other opponents of prostitution say that the practice endangers vulnerable girls who could fall prey to pimps, and that it breeds crime and drug use. While john-shaming is well known as a preventive tactic, it's unclear how well it works.

"That's the million-dollar question," Shively said.

His three-year study found about 60 percent of police departments that arrest prostitution clients publicize their identity in some way, Shively said. An interactive U.S. map based on the study will be available next month that will allow users to click to see more about an area's tactics.

Places including El Paso, Texas; Chicago; St. Paul, Minn.; and Chattanooga, Tenn., have been or are currently home to police- or community-sponsored shaming pages. In Baltimore, a community program has encouraged residents to attend court in prostitution cases to shame offenders and urged judges and prosecutors to follow through with charges and penalties.

Sometimes, police departments send so-called "Dear John" letters to the homes of owners of cars seen cruising for street walkers. Others require offenders to attend classes aimed at preventing recidivism by educating first-time offenders about the dangers of prostitution.

But the efforts face criticism, too.

The shaming techniques are particularly damaging because they publicly humiliate people prior to trial, for what remains a relatively minor offense, said Laurie Shanks, a professor at Albany Law School.

"The chance of a completely innocent person having their life destroyed was astronomical," she said. "It was worse than the scarlet letter. At least the scarlet letter happened after the trial. It's closer to branding, where you can't take it off once the harm has been done."

Collateral damage done to families by shaming is "a very legitimate concern," Shively said.

"Imagine the 13-year-old girl who goes to school and her father's name is in the paper," he said.

In Kennebunk, the superintendent of schools has directed teachers and staff to be on the lookout for students who may be teased or have trouble coping because they have relatives on the list.

Eliot Spitzer resigned as governor of New York in 2008 after the father of three was accused of a rendezvous with a prostitute. He remains married and hosts a cable news show. Actor Hugh Grant emerged little worse for the wear after being arrested in the company of a prostitute in Los Angeles in 1995.

Historically, Shively said, police have arrested women and girls who provide sex for sale. But efforts to arrest customers can be traced to the 1960s and has gradually increased. In the intervening period, the percentage of women in sex arrests in the U.S. has fallen from 90 percent to 65 percent, Shively said.

In 1999, Sweden took the approach of decriminalizing the sale of sex but continuing to punish those who paid for it, prompting even more discussion about the best way to combat the sex trade.

A notable exception to targeting prostitution customers is in the federal system, where prosecutors say johns would have to cross state lines or take advantage of vulnerable victims such as children to justify the expense of a federal case.

Barbara McQuade, U.S. attorney in Detroit, said she does not believe her office prosecuted any of the 30,000 or so clients of a decade-long sex ring that made millions of dollars by dispatching prostitutes nationwide.

"We were looking for the organizers," she said. "In the federal system, we exercise a lot of discretion because we have scarce resources. We can't arrest and prosecute every john hiring a prostitute."

The law enforcement community is starting to realize that the women in the sex trade are frequently victims of circumstances so cruel that their work is carried out under pressures more common in slavery, said Norma Ramos, executive director of the Coalition Against Trafficking in Women.

It's all part of changing the public's perception of prostitution, she said.

"The idea is to discourage men from the notion that they have the right to buy the bodies of lesser privileged women and children for sexual gratification," Ramos said.

"We have to move away from the 'Pretty Woman' model and towards understanding that prostitution's pretty ugly."