  Walker (p. 85) extends her notion of default trust to include zones of “diffuse default trust,” as also illustrated in her example involving the major airline corporation. Consider the many ways that responsibility can become “diffuse” when distributed over a vast zone of trust such as a commercial airline (Walker), or a major SEC like Google which also qualifies as a zone of diffuse-default trust comprising a diverse range of agents (both human and non-human). Among the non-human entities in that zone are artificial electronic agents (bots) who “operate behind the scenes,” both with humans and other artificial agents. The latter kinds of entities also include multi-agent systems that can “act” in limited ways on behalf of an SEC. For a detailed description of how Walker’s model can be applied in digital contexts, including zones of diffuse default trust comprising both humans and multi-agent systems, see the analysis in Buechner and Tavani (2011).