Consider the case study on MeaningOfIdentity. What information can you gain from either the IP of the broadcast message or a signature?
What context comes with it? What is a machine adding by lending the weight of its signature?
You certainly bring with it the entire context of what its contributed elsewhere on the system. However, even that is muddled because the system is atemporal (because of the weak versioning system) even though the world is not.
Thus, as the machine gathers more data, its preliminary findings may become invalidated. Or, even worse, as the programmers work furiously to improve the code and squash all bugs, the quality of the postings improve over time. How do you assess the quality of an identity?