 Why did AT&T originally retain ownership of the phones at the endpoints?
The Web, after all, is less than a generation old. These two features−the global scale of interdependence of human action, and the systematic acceleration of innovation, make contemporary life a bit like a slow motion disaster, in one important respect. That is why we have seen many more systems take on a loose, human centric model in the last decade and a half: from the radical divergence of Toyota’s production system from the highly structured model put in place by Henry Ford, to the Internet’s radical departure from the AT&T system that preceded it, and on to the way Wikipedia constructs human knowledge on the fly, incrementally, in ways that would have been seen, until recently, as too chaotic ever to work (and are still seen so be many). Trains and planes, telegraph and telephone, all brought many people into the same causal space. The solution to this increased complexity in the late 19th, early 20th century was to increase the role of structure and improve its design. During the first two-thirds of the twentieth century, this type of rationalization took the form of ever-more complex managed systems, with crisp specification of roles, lines of authority, communication and control. The ambition of these approaches was to specify everything that needed doing in minute detail, to enforce it through monitoring and rewards, and later to build it into the very technology of work−the assembly line. The idea was to eliminate human error and variability in the face of change by removing thinking to the system, and thus neutralizing the variability of the human beings who worked it. But the impulse to build fully-specified systems, designed by experts, monitored and controlled so as to limit human greed and error and to manage uncertainty, was basic and widespread. It underlay the development of the enormously successful state bureaucracies that responded to the Great Depression with the New Deal. In technical systems too, we saw in mid-century marvels like the AT&T telephone system and the IBM mainframe. For a moment in history, these large scale managed systems were achieving efficiencies that seemed to overwhelm competing models: from the Tennessee Valley Authority to Sputnik, from Watson’s IBM to General Motors. The increasing recognition of the limits of command-and-control systems led to a new approach; but it turned out to be a retrenchment, not an abandonment, of the goal of perfect rationalization of systems design, which assumed much of the human away. What replaced planning and control in these systems was the myth of perfect markets.
 To ensure the proper functioning of the networking and monitoring of customer behavior.
 To prohibit customers from connecting unlicensed phones at the endpoints.  To exclude competitors.  To ensure the proper functioning of the networking and monitoring of customer behavior.  To make the most profit.