A generation ago, even after technology had advanced, many rural residents clung to the party line telephone systems that allowed neighbors to listen in on one another’s conversations. Now they are gravitating toward open community forums online, said Christian Sandvig, an associate professor at the University of Illinois at Urbana-Champaign.

“Something about rural culture seems to make people want to have conversations in public,” said Mr. Sandvig, who has studied the use of social media sites in rural areas.

Topix, a site lightly trafficked in cities, enjoys a dedicated and growing following across the Ozarks, Appalachia and much of the rural South, establishing an unexpected niche in communities of a few hundred or few thousand people — particularly in what Chris Tolles, Topix’s chief executive, calls “the feud states.” One of the most heavily trafficked forums, he noted, is Pikeville, Ky., once the staging ground for the Hatfield and McCoy rivalry.

“We’re running the Gawker for every little town in America,” Mr. Tolles said.

Whereas online negativity seems to dissipate naturally in a large city, it often grates like steel wool in a small town where insults are not easily forgotten.

The forums have provoked censure by local governments, a number of lawsuits and, in one case, criticism by relatives after a woman in Austin, Ind., killed herself and her three children this year. Hours earlier she wrote on the Web site where her divorce had been a topic of conversation, “Now it’s time to take the pain away.”

In Hyden, Ky. (population 365), the local forum had 107 visitors at the same time one afternoon this month. They encountered posts about the school system, a new restaurant and local arrests, as well as the news articles and political questions posted by Topix.