The methodology of any domain depends, first, on clarifying what types of object are being researched – indeed can exist – in that domain: that is, on clarifying the ontology of that domain. The ontology of social media might seem wholly unproblematic: social media sites are certainly infrastructures with considerable, even massive, presence in our lives, the focus of our everyday habits of checking and updating, circulating and sharing. When 1.5 billion people are active monthly users of one leading social media platform alone (Facebook), then the ‘object’ of study is hardly trivial. But what type of object are we studying exactly? Again from one point of view, the question seems straightforward: Facebook, Twitter, and other sites of social media activity ...