After a weekend of rumors, Microsoft officially announced Monday that it will acquire the code repository site GitHub for $7.5 billion in stock. The platform is an important resource for some 28 million developers and home to billions of lines of open source code. It's in many ways a natural fit for Microsoft, which has in recent years warmed up to open source.

But the beloved developer platform may also introduce moderation headaches. Microsoft will soon need to formally decide what will happen to the many GitHub repositories that conflict with its own interests. The tech giant will face similar content moderations challenges that peers like Facebook and Google have, but with code instead of speech.

Created over a decade ago, GitHub is where developers at nearly every major software organization, from Google to NASA, collaborate. It hosts projects as diverse as Bitcoin's code and all of the German government's laws and regulations. The platform functions as a kind of social network for coders; their contributions to the site can serve as a stand-in for a traditional resume. Anyone can publish open source code to GitHub for free; the platform makes money by charging individuals and corporations to keep their code private.

GitHub's 85 million repositories help to make it one of the world's most popular websites. They include, however, projects that GitHub's new owner might take issue with.

Microsoft's Burden

Take as an example the Xbox emulators hosted on GitHub. These often-homemade programs allow people to play console games on their computers. Microsoft owns Xbox, and ostensibly loses money when gamers decline to buy consoles and play on desktop instead. These emulators pose an interesting problem: Microsoft will likely anger developers if it takes them down, but not doing so would be against its own business interests. It's a simple example, but there are plenty of other conflicts that arise from Microsoft gaining control over GitHub.

Microsoft will have to think carefully about whether it wants to host tools that enable people to create things widely thought of as harmful.

GitHub also houses the code that allows people to create deepfakes, nonconsensual porn videos that use artificial intelligence to transpose one person's face onto another's body. First reported by Motherboard, deepfakes have since been banned by nearly every major social network. But the code used to create them still lives on GitHub, presenting a potential ethical issue for Microsoft.

And in many ways, moderating code used to create objectionable content is thornier than simply banning the content itself. One could theoretically argue, for example, that continuing to host the deepfake code serves an educational purpose.

Taking down one piece of objectionable content is not the same as "taking down the code that could maybe generate a million pieces of content," says Sarah T. Roberts, an assistant professor of information studies at UCLA who researches content moderation. "The implications are different."

Code that helps to create objectionable content isn't itself objectionable, but Microsoft will have to think carefully about whether it wants to host tools that enable people to create things widely thought of as harmful, though not outright illegal. It's a question that other user-generated content platforms, like Facebook, don't have to consider in the same way.

International Headaches

Microsoft may also face problems with GitHub overseas, specifically in China. Unlike sites like Facebook, China's government cannot simply block GitHub wholesale, which would prevent its own developers from accessing valuable open source code. But GitHub also hosts content that the country's government would rather censor, like readings related to the 1989 student-lead protests in Beijing's Tiananmen Square.

In fact, analysts believe that in 2015 China launched a denial of service attack against specific GitHub pages, attempting to flood them with traffic in an effort to get them taken down. They included a page for GreatFire, which provides tools for circumventing China's internet censorship, as well as the Chinese edition of The New York Times. A year later, China tried to get GitHub to remove content simply by asking nicely. GitHub declined. Some worry Microsoft may be more willing to appease similar Chinese demands, since the company has other business interests there.