Wikipedia is renowned for its openness—a Web site so democratic that anyone can edit its pages—but despite the reputation, the site has always been mostly edited by an elite coterie of contributors. And as many of Wikipedia's less hardcore editors flee the site, the free encyclopedia is moving even further in that direction, amounting less to "the wisdom of crowds" than the wisdom of the "in-crowd."

This week, The Wall Street Journal reported that a growing number of Wikipedia's editors are throwing in the towel, fed up with the many rules the site has instituted as it has matured. The story suggested the exodus could threaten "the brand of democratization that Wikipedia helped to unleash over the Internet—the empowerment of the amateur."

“No matter what you write, you are bound to offend somebody over grounds of neutrality, naming convention, original research, etc. The only way to contribute is to be as extremely dull as possible.”

That brand is a myth. "The idea that a lot of people have of Wikipedia is that it's some emergent phenomenon—the wisdom of crowds, swarm intelligence, that sort of thing… like we're a lot of ants, working in an anthill," Jimmy Wales, the site's co-founder, has said. "It's kind of a neat analogy, but it turns out it's actually not much true."

Wales examined the numbers several years ago and was surprised to learn that the most active 2 percent of users had performed nearly 75 percent of the edits on the site. "There's this tight community that is actually doing the bulk of all the editing," he said. "I know all of them, and they all know each other."

This clique of users enforces Wikipedia's bewildering list of rules—policies covering neutrality, verifiability, and naming conventions, among other areas. It's not difficult for newcomers to run afoul of these regulations when they try to edit an article.

"Someone will almost blithely refer to a policy, like 'check WP:UNDO,' and you have to read [what are] almost like these technical manuals, and you still don't know how they arrived at this decision," says Justin Knapp, a student at Indiana University who regularly contributes to the site. "If you're a new user just trying out Wikipedia and you notice some problem that you want to fix, but your changes are reverted immediately, what are you supposed to do? … It can be intimidating."

The Wikipedia elites may be partly to blame for the site's diminishing participation. In a survey conducted this year, nearly a quarter of respondents who declined to contribute to Wikipedia said they were "afraid of making a mistake and getting 'in trouble' for it," among other reasons.

Former contributors to the site attest that the ruling "in-crowd" is a turnoff for new users.

"You just can't sit down and write an honest, creative, and argumentative article peacefully anymore," writes one former editor, who uses the handle "Wikimachine" on the site, in an email. "No matter what you write, you are bound to offend somebody over grounds of neutrality, naming convention, original research, etc. The only way to contribute is to be as extremely dull as possible."

Wikimachine says he has not contributed to the site in about two years, following a heated dispute over an article about the Liancourt Rocks, a group of islets in the Sea of Japan. Wikipedia's arbitration committee sanctioned Wikimachine with a one-year ban.

For Eric Lerner, a physics researcher who is the author of the 1991 book The Big Bang Never Happened, the last straw was a series of disagreements involving an article on plasma cosmology; administrators ultimately asked him to stay away from articles related to his work. He contends that the site's democratic reputation is undeserved: "[Editing Wikipedia] becomes an enormous waste of time because you end up fighting people who are single-mindedly devoted to their role in Wikipedia, and in the end, what ends up getting published is not decided by 'the wisdom of crowds,' it's decided by the administrators."

At the same time, these administrators undoubtedly play a critical role in maintaining Wikipedia's professionalism, volunteering untold hours to clean up vandalism and improve the quality of articles. And their apparent distrust of newcomers is not entirely without merit. "They're reflexively suspicious of everyone from watching people attack Wikipedia over all the years," says Clay Shirky, a professor at New York University who sits on the advisory board for the Wikimedia Foundation, the nonprofit group that runs Wikipedia. "If everyone who works at Britannica were fired, the encyclopedia would become out of date and less useful over time as new articles weren't added, and old ones weren't updated, and would become considerably less valuable over time. But if everyone who really cares about defending Wikipedia didn't log in this week, it would be gone by Thursday."

This spirit of professionalism, however, risks alienating newcomers who may have unique or esoteric knowledge to contribute. Intelligent observers have suggested that some of Wikipedia's most valuable knowledge may originate with these casual contributors, and that's why the report that fewer users are adding to the project is so troubling. If the Wikipedia clique fails to take steps to embrace these newcomers, the site may run out of fuel, and that's bad news for anyone who relies on the world's largest encyclopedia.

Nicholas Ciarelli is an assistant product manager at The Daily Beast.

Benjy Sarlin contributed to this story.