We all grew up hearing that we should not litter in the park, because a clean park is something everyone needs. But do we think of our digital world the same way? The stream of news, posts, videos, and data we swim in every day is also a shared space—one that can get polluted by falsehoods, manipulation, and carelessness. This chapter is about seeing that digital environment as a commons, and why protecting it is a responsibility none of us can leave to someone else.