For 12 years, Peggy Denby has been the face of a neighborhood counterattack on crime along the faded stretch of Ponce de Leon Avenue. During that time, she has waged war on an all-night gay nightclub, open-air drug markets, transgender prostitutes, street hoodlums, lenient judges and the city’s largest homeless shelter.

“Midtown’s Meanest” woman, as she is known, is tired. And so, like the characters in the movie “Lost in America,” she and her husband have sold their home, bought an RV and are heading out to wander America, no particular destination in mind.

“We did this in a big way,” she said of her retirement plan, which resembles how she went about cleaning up this neighborhood as a founder and the leader of the Midtown Ponce Security Alliance.

Denby and her husband, Don Jones, moved to Midtown in 2001 thinking urban life would be “cool,” as she puts it, but they were immediately aghast at the surroundings. “The vagrants, the drugs and the prostitutes; it was a food chain, it was like an eco-system,” she recalled. “We were living with Third World conditions on the streets.”

She found that residents were tired of those conditions but perhaps no longer shocked. So she and a core of volunteers concocted a crime-fighting 501(c)4, collected money to hire off-duty cops (they pulled in $120,000 a year at its height) and then took on Backstreet, the 24/7 gay disco that once hosted Cher and saw patrons spill out onto the streets at all hours.

“It was the giant sore that kept this all alive,” she said of the club that was forced out of business in 2004. She lives in a condo tower that stands where sweaty men once boogied long into the night. It’s ironic, she knows.

Denby and other founders knew there would be blowback from their efforts, so she became the face of the franchise: “We knew we’d get criticized, so we decided. I was the little old lady with white hair. No one would pick on me.”

Things didn’t work out that way. Some have denounced her “fortress mentality.” Project Q Atlanta, the popular gay online site that tagged her as Midtown’s Meanest, once called her “the gray-haired bitter pill (who) fueled the fight against Backstreet,” adding she “is such a bigoted grouch that she can’t allow herself even a whiff of compassion” when discussing homeless people.

Denby, of course, does not appreciate the criticism but plugs along, assured the attacks are “unfounded and irrational” and she is simply “fighting for property values and quality of life.”

In a recent interview, she mimicked critics who said she should have known better, that the prostitutes and vagrants “were here first, they were part of the fabric of the community.’’ She considered the argument, smiled and added, “Hopefully a washable fabric.”

The off-duty APD cops have helped scare off some of those kicking in doors during the day and looting cars at night. The open air drug markets aren’t as open air. The prostitutes are no longer as plentiful. Streetlights were repaired, bushes where criminals lurked have been shorn, hideaways where homeless camped have been discovered. The Broken Windows theory has been the group’s North Star.

Retired APD Sgt. Barry Miller, who has started and run a couple dozen community policing operations, was surprised to hear of Denby’s plans to hit the road.

“Wow. She’s not afraid of change,” he said. “She’s not afraid of much.”

Miller said Denby was on-scene when he made his first arrests while working with the security alliance.

“She was standing there pointing them out.”

John Wolfinger, a resident who heads the neighborhood watch in in neighboring Virginia Highland, says she’s his mentor, a guiding light who has helped many other communities.

“She’s very tough and just doesn’t give up,” he said. “She stepped up to the forefront when others wouldn’t.”

Denby’s group each month sends out a blog to members with a list of The Unwanted, a collection of local ne’er –do-wells who have plagued the community with crimes ranging from garden-variety nuisance stuff to scary-as-hell felonies.

“We know who our criminals are and they know that we know who they are,” she said.

Her main crime-fighting partner is a resident named Steve Gower who roams the streets at all hours with a high-beam flashlight and video camera, harassing those who harass their neighborhood. Many a prostitute and john has been surprised (to say the least) by a high-beam intrusion.

Her group’s constant calling out on the transgender prostitutes, says Matt Hennie, founder of Project Q Atlanta, is a “nasty campaign that demonizes and dehumanizes people.”

Denby argues that bands of prostitutes roaming the streets is death for a neighborhood. Nothing says “Ick!” about a community more than used condoms in the gutter.

Her one regret? It’s that the homeless shelter at Peachtree and Pine streets remains. The city has long fought to strangle the shelter, which often houses 700 (mostly) men a night. Denby and other critics have branded the place a flophouse that enables druggies, drunks and the mentally unhinged to continue their bad behavior.

Anita Beaty, head of the Metro Atlanta Task Force for the Homeless, is like Denby, a diminutive, stubborn, white-haired grandmother who is sure in her cause and defiant to critics.

The two have become each other’s nemesis, although they’ve never met. Denby chuckled at their duality. “Two bitchy women fighting each other,” she said. “Both committed.”

The shelter has lost millions in dollars in financial support because of the civic effort to close it, has lost a judge’s decision but still slugs it out in court.

“The shelter will outlive me, that makes me sad,” said Denby, who also headed the city’s Keep America Beautiful campaign aimed at increasing recycling and combating litter. “I don’t know; it’s like a triple-headed snake. You can’t kill it.”

Beaty was thrilled to hear of Denby’s upcoming road trip, laughing uproariously at the news.

“That’s the best thing I’ve heard in a long time,” said Beaty. “She’s had a lot of venom that seemed to be unrestrained.”

Denby shrugs at such opinions. She’s heard them all. They used to bring a tear. But no longer.

The crime-fighting clean-up lady said she was fueled by righteous indignation all these years. “What makes me go? It’s knowing the difference between right and wrong. Others might see it and not like it but not do anything.”

Denby said she did her part. Now it’s someone else’s turn.