They have had it in the Duboce Triangle. It’s one thing to find trash on the sidewalk or to be panhandled on the corner. But Stephanie Tang and other residents can’t believe vandals are destroying the neighborly little touches they’ve been adding.

About two years ago, Tang had the idea to join the nationwide Little Free Library movement, which, according to its website, has more than 40,000 installations across the country. Small, colorful containers with shelves are stocked with free books. All patrons have to do is return the books when finished.

The idea is to encourage neighborhood interaction, but the Little Free Library at Noe and 15th streets has become an exercise in frustration.

“It’s really just been one thing after another,” said Peter Kupfer, another resident. “It was vandalized. It was knocked down. Someone set fire to it. It was knocked apart and in pieces on the street. It was stolen completely, so a neighbor donated a cabinet, which we had painted and refinished.”

Last week, though, was the topper. The sponsors had bolted the Little Free Library to the sidewalk with metal braces.

“And they just ripped it out of the pavement,” Kupfer said.

There have been offers to donate a replacement, but Tang says she’s not sure it’s worth the effort.

Granted, any urban street is prone to pointless vandalism. But Tang sees the saga of the Little Free Library as symptomatic of a larger concern.

“We are neighbors who are desperately doing what we can to build a community,” she said. “But you know what? The crazies are winning, and the city is enabling them.”

The Duboce Triangle is a lovely area just above the Castro with old growth trees and well-kept homes. It’s a good place to walk your dog to Duboce Park or stroll down to restaurants along Market Street. But it’s also near the Haight, and that neighborhood’s issues spill over.

“It’s really getting unpleasant,” Kupfer said. “There’s not a day that goes by that I go out of my apartment and I don’t contact someone talking to himself.”

Tang has contacted police when the Little Free Library was vandalized, but to no effect.

“I have filed police reports for when it was set on fire and the two times it was stolen,” she said. “The police just send a message saying your report has been filed.”

Tang doesn’t know exactly who is trashing the Little Free Library, but in general, she suspects that “the level of insane behavior that is accepted on the street” is to blame.

Tang has videotaped people stealing her mail. She was menaced by a man who threatened to punch her and her neighbor, who was holding a baby. One man is such a chronic offender — vandalism, ringing her doorbell at 4:30 a.m. — that Tang found out his name and looked up his Facebook page so she could give a better description to the police.

Not that it made any difference. Last week the guy was passed out on a neighbor’s stoop. Police took him away, but Tang expects he’ll be back.

Through it all, she and the neighbors have taken all the suggested steps. They formed a neighborhood watch group, hosted a block party for beat cops, joined the Community Advisory Board, became members of the homeless-outreach group Castro Cares, met with an assistant district attorney and walked the neighborhood with Mayor Ed Lee’s new fix-it team.

None of it seems to have helped.

“I don’t know what else we can do, aside from joining the police academy,” Tang said.

It may come to that. The people who have been vandalizing the Little Free Library are one stubborn and entitled group. At one point the library folks were putting stamps on the books for identification.

“And we got a note from a guy,” Tang said. “It said: ‘Can you please not stamp the books? It makes it hard for me to sell them.’”

Randy Shaw, a Tenderloin booster and director of the Tenderloin Housing Clinic, became accustomed to getting the same response whenever he suggested opening a restaurant on the neighborhood’s gritty streets.

“The Tenderloin?” Shaw says he usually heard. “What do you have on Valencia Street in the Mission?”

But when he approached well-known New York City restaurateur (and San Francisco resident) Fritz Quattlebaum, there was immediate interest. With the help of the Mayor’s Office of Workplace Development, a financial package was put together for a site at Eddy and Leavenworth.

It’s not exactly one of the city’s garden spots, but at last week’s grand opening of the restaurant, the Black Cat, optimism was high.

Quattlebaum’s group took over a defunct Chinese restaurant that had been “modernized,” which meant, for example, that a false ceiling had been installed just 7 feet above the floor. They took that out, raised the ceiling to 20 feet, removed wall coverings to reveal brick walls and redid the basement, which now has a stage and booths for supper dining and entertainment.

The club is named for the original Black Cat nightclub, which officials shut down nearly 100 years ago amid a spasm of civic morality.

For the new place to hark back to the old name lends a nice historic touch. It also suggested a slogan:

“Nine lives,” the menu reads. “Don’t waste one.”

C.W. Nevius is a San Francisco Chronicle columnist. His columns appear Tuesday, Thursday and Saturday. Email: cwnevius@sfchronicle.com Twitter: @cwnevius