Societies are run by machines, just like Deleuze said; and how Plastic Pill has very well summarised in his pod episodes, links below. Machines are systems that classify people by different properties and later exercise control over them, look to Foucault on how different systems oppress and control people to adhere to norms. Some systems have evolved to use access control rather than direct discipline, eg design infrastructure that promotes one mode of transportation. In the end, whatever way systems apply to us, they see us as sets of properties rather than subjects, now we are negated. In this sense, capitalism is posthuman, because it is changing the subject from humans to processes. We as humans can only have a human-oriented view of the world.
I think that the negation of human subjects is just a coincidental result of post-modern systems evolving. The answer to this negation should be a negation of negation. Thinking of a humanistic system, humanistic socialism as Fromm put it, ergo has humans as subjects. Simple enough but I think of moving away from discipline and control to enabling and sustaining. Only then we can go a step forward to another posthumanism (post-posthumanism maybe) that is more livable and life-oriented.
Pill Pod 74 - Post Posthumanism
Pill Pod 78 - The Posthumanism Manifesto
Deleuze - Control Societies & Cybernetic Posthumanism (Plastic Pill)