A marginal note in anthropologist Tom Boellstorff ’s ethnographic study ‘Coming of Age in Second Life’ refers to a strange experience residents of Second Life (SL) sometimes have. Boellstorff notes that ‘Volunteer helpers often found new residents of Second Life asking them “Are you human?”—in other words, are you automated or not?’ (Boellstorff, 2008, p. 131). This episode is very illuminating because it shows an important aspect of communication in virtual worlds and computer games to which little attention has been paid so far: These environments are not only inhabited by human-controlled avatars, but potentially also by non-humans, who are allegedly said to be able to socialize. Besides a human population, platforms like SL have also spawned a population of social bots , ranging from simple chat bots to sophisticated ‘embodied conversational agents’ (ECAs). From this follows that users of online environments have to deal with a special kind of ‘virtual contingency’ (Esposito, 1993) when communicating with each other. The situation is not only framed by anonymity, but also by uncertainty about the (human) status of the virtual counterpart. As a consequence, online environments like SL blur the borders between the social world of humans and the technical world of machines.