This year, Wikipedia is celebrating 25 years as the internet’s encyclopedia that anyone can edit. In its first decade, the quirky experiment for passionate nerds exploded in popularity. It became a ubiquitous information resource and a homework helper for schoolkids, much to the dismay of skeptical teachers.

In its second decade, amid the public’s growing dissatisfaction with the mangling of facts in popular discourse, it took on a new role as information infrastructure, helping categorize and validate information worldwide. Wired magazine deemed it “the last best place on the internet.” The hope was that the volunteer project could serve as the antidote for misinformation. Platforms from Facebook and Twitter to Alexa and YouTube began embedding Wikipedia material to ensure that users had context for what they read or saw.

That role has become more acute in recent years. Artificial intelligence developers have relied deeply on Wikipedia to train the large language models behind popular chatbots, which weight clean, reasonably reliable information sources more heavily than the rest of the web. Chatbots and AI-powered search engines have intensified Wikipedia’s significance, even as they siphon its readers by answering questions directly, with fewer people going to the source site itself.

But as Wikipedia’s importance – and size – has grown, the size of the volunteer corps that maintains it has not, and the number of volunteer administrators, a key moderation role, has shrunk.

I’m a researcher who studies social media platforms. I analyzed two decades of the site’s moderation records to understand the effect of these conditions. I found changes in behavior that appear to prioritize content quality while weakening the project’s ability to recruit and retain new volunteers.

Under pressure

As Wikipedia has become more prominent, its resistance to top-down control has made it a target for people who have political or financial power. There is frequent news about takedown demands and censorship abroad, investigations and threats to its nonprofit status in the U.S., and, outside the U.S., volunteers have been arrested and imprisoned.

The Wikipedia community is also sensitive to its rising importance, but not in the way you might think. Contributors are keenly aware of political rhetoric that takes aim at their project or threatens volunteers. But the chief effect on volunteers has been a sense of heightened obligation to their global readership, which has gradually increased quality standards.

As a longtime volunteer myself, I’m often taken by the community’s perseverance and the people’s desire, above all, to get on with their work of summarizing the world’s knowledge.

The English language Wikipedia has maintained a reasonably steady number of contributors since 2010 – about 40,000 – yet its size and importance have grown. In 2006, it contained 1 million articles; in May 2025, it passed 7 million. A new issue is an influx of low-quality content generated by large language models.

The steady decrease in administrators is especially concerning. Administrators are a subset of trusted users, elected by the community at large, who are given powers such as the ability to delete articles or block users from editing. Unlike moderators at for-profit platforms, Wikipedia cannot simply hire more administrators. There are slightly more than 800, down from almost 1,800 in 2011, and they’re not all active.

So Wikipedia’s role has grown, but it is held together by a relatively small, shrinking community of unpaid volunteers. To keep up, the community in general and administrators in particular have had to raise their efficiency, making trade-offs between maintaining open participation and raising article quality. These trends and their costs are well documented. They are clearly visible in one of the basic administrator routines: blocking.

Shown the door

Blocking is when an administrator determines that a user is so detrimental to the project that they must be prevented from making any further edits. The blocked user can still read Wikipedia, but cannot change it.

Unlike the opaque moderation systems at the large internet platforms that I normally study as a researcher, such as YouTube or TikTok, nearly every administrative action on Wikipedia is recorded in a public log. I used these logs for a study analyzing all 20 million blocks made on the English language Wikipedia over the past two decades. I looked for patterns in frequency, duration and reasons for a block. I also assessed whether those patterns corresponded to the growing trade-offs between openness and quality.

I found that the frequency of blocks has risen sharply in recent years due to administrators using bots to preemptively block proxies. Proxies are services such as virtual private networks, or VPNs, that people use to conceal their identity, often to facilitate abuse or manipulation on Wikipedia. One of these bots, ST47ProxyBot, was so active that it accounted for the most blocks in the site’s history. Preemptive proxy blocking likely prevents damage, but it can also occasionally stop good-faith contributors. Given the increasing popularity of AI agents and their disruptive potential, this practice is likely to continue to expand.

I then removed proxy blocks from the analysis so I could focus on humans who were blocked and why. In the early years, administrators made the majority of blocks for vandalism: intentionally bad or nonsensical edits. That has shrunk to about a quarter of all blocks today. Blocks have risen for promotional editing and for sockpuppetry — when one person creates multiple accounts to manipulate content. These shifts speak to Wikipedia’s increased prominence as a target for influence.

Signs of stress

What I found most interesting was administrators’ greater use of generalized reasons for blocking, such as “disruption.” Wikipedia defines disruption as “a pattern of editing that disrupts progress toward improving an article or building the encyclopedia.” But citing this can mean nearly anything seen as counterproductive. The trend is partly explained by “disruption” being in a list of boilerplate rationales that administrators can choose from instead of entering a customized reason.

But it’s also the kind of trend I would expect to see in a labor force stretching to keep up. Administrators don’t act arbitrarily, and their actions are publicly logged and closely scrutinized. A loss of trust leads to an administrator losing their position. But to be effective, general explanations for blocks rely on shared understandings that new users may not have. Research on blocked users shows that when a sanction feels vague or unfair, volunteers are more likely to walk away – or dig their heels in – rather than reform. Good for efficiency; bad for bringing new users into the fold.

Blocks are also lasting longer on average. That, together with preemptive blocking and generalized rationales, suggests that the volunteer community is increasingly prioritizing prevention, efficiency and content quality over efforts to rehabilitate new users.

And the work is not spread evenly among the roughly 800 administrators: For many years, the most active 10% of administrators have made about 80% of the blocks. That high number dropped to 37% in 2024, largely due to changed activity by a single prolific administrator.

Bearing the cost

Wikipedia’s openness is part of how its volunteer community grew in the first place. Now that Wikipedia has become infrastructure, that community is rationing openness to preserve quality for readers. If Cory Doctorow’s zeitgeist-capturing idea of platform “enshittification” is fundamentally about ruining the experience of end users for the sake of the shareholders, Wikipedia is attempting something like the opposite. The end-user experience is being preserved, and the people behind the scenes are bearing the cost.

Wikipedia has adapted remarkably well in its evolution from early web experiment to one of the most important global sources of information. The open question, for a resource that so many humans – and now machines – rely on, is how long the volunteer system can keep enduring the cost.

Ryan McGrady is also a volunteer contributor to Wikipedia and is affiliated in a volunteer capacity with Wikimedia New York City.