Wikipedia copyright: How free knowledge stays protected

When you read a Wikipedia article, you’re using content that’s legally protected by Wikipedia copyright, a licensing system that lets anyone use, share, and modify content as long as they give credit and keep it free. Also known as Creative Commons Attribution-ShareAlike, it’s the backbone of everything Wikipedia does—no ads, no paywalls, just open access. This isn’t just a legal formality. It’s what lets students, journalists, and researchers build on Wikipedia’s work without fear of lawsuits. Without it, AI companies could scrape millions of articles, train models on them, and sell the results—without giving anything back.

That’s why the Wikimedia Foundation, the nonprofit that runs Wikipedia and its sister projects. Also known as Wikimedia, it’s the legal guardian of the platform’s open model is fighting back. They’ve started building tools to detect when AI firms use Wikipedia content without following the rules. They’re pushing for laws that require AI companies to disclose training data. And they’re working with lawyers to make sure copyright isn’t twisted into a tool for control. This isn’t about locking content away—it’s about making sure the people who built Wikipedia still benefit when others profit from it.

Wikipedia copyright also shapes how editors work. Every edit must come from a source that’s either public domain or licensed to allow reuse. That’s why you won’t find copyrighted photos, song lyrics, or book excerpts unless they’re used under strict fair use rules. It’s why editors reject articles copied from blogs or news sites that don’t allow redistribution. This system isn’t perfect—it slows things down, and sometimes good content gets tossed out. But it keeps Wikipedia honest. It stops corporate interests from turning the encyclopedia into a marketing tool.

And it’s not just about text. The same rules apply to maps, audio clips, and even data from Wikidata. When museums, libraries, and archives share their collections through GLAM-Wiki projects, they do it because they trust the copyright system to protect their work while letting it reach the world. The same trust keeps volunteers coming back. They know their edits won’t be stolen and sold. They know their contributions stay free.

What you’ll find below are real stories about how this system works—or breaks. From how AI companies test the limits of copyright, to how editors fight to keep public domain material from being locked behind paywalls. You’ll see how news corrections ripple through Wikipedia, how edit filters block copyright violations before they spread, and why the Wikimedia Foundation is spending millions to defend open knowledge in court. This isn’t theoretical. It’s happening right now, in real time, on every article you read.