One of the most ubiquitous features of the internet is the ability to link to content elsewhere. Everything is connected via billions of links and embeds to blogs, articles, and social media. But a federal judge’s ruling threatens that ecosystem. Katherine Forrest, a Southern District of New York judge, ruled Thursday that embedding a tweet containing an image in a webpage could be considered copyright infringement. The decision can be appealed, but if it stands and is adopted by other courts, it could change the way online publishing functions.

Here’s what happened: In 2016 Justin Goldman took a photograph of NFL quarterback Tom Brady and Boston Celtics president and manager Danny Ainge in the Hamptons and posted it to his Snapchat Story. The photo was newsworthy because at the time, the Celtics were reportedly trying to recruit NBA star Kevin Durant. It was interesting that the team's manager brought along someone who played an entirely different sport. The photo soon went viral, and eventually was posted on Twitter and Reddit by several different users. Online publications including Breitbart, Yahoo, The Boston Globe, and Heavy.com then embedded the tweets into news stories. Goldman, backed by Getty Images, sued—arguing that the publications had infringed on his copyright to the photo.

This week, Judge Forrest sided with Goldman and argued that the publications violated his “exclusive display right,” despite the fact that they didn’t host the photo on their servers (more on that in a second). By simply embedding a tweet—a function which Twitter makes simple—Forrest says the publications engaged in a “technical process.” She readily admits that none of them downloaded the photo and then uploaded it to their own sites, but, she argues, it doesn’t matter that the publications weren’t hosting the photos themselves.

Judge Forrest based her decision on two foundational technology copyright cases. One is Perfect 10 v. Amazon from 2007, where the Court of Appeals for the Ninth Circuit ruled that Google could display full-size copyrighted images in search results, as long as it was simply linking to the content, not hosting it themselves. That case established what is known as the "server test"—the idea that the entity hosting the content should be liable, not someone who links to it.

The idea is that the linker doesn’t necessarily know a piece of content is infringing, and cannot control what exactly the displayed content will be. Consider for example when a tweet is embedded by a news site and then deleted by its author. The tweet disappears from the publication, because they were never hosting it in the first place.

Forrest argues that the server test shouldn't apply to news sites because they don't function in the same way as search engines. She says search engines are services "whereby the user navigated from webpage to webpage, with Google's assistance." In her ruling, she says news sites just display embedded content to a user—whether or not the user "asked for it, looked for it, clicked on it, or not."

The Electronic Frontier Foundation's senior staff attorney Daniel Nazer believes Forrest's interpretation of the Perfect 10 case is new, and not what the original ruling argued. "This is a distinction that's being drawn really for the first time in this case," he says.

The second case Forrest cites concerns broadcasting service Aereo's Supreme Court defeat from 2014. The court ruled in that case that Aereo couldn't broadcast copyrighted television channels over the internet simply because it was utilizing technology other than radio waves. Forrest uses this case to make the point that "mere technical distinctions invisible to the user should not be the linchpin on which copyright liability lies." What she means is that embedding is different than just re-uploading a photo technologically, but the result for the user is the same—a photo appears.