The network only refers to the transit medium if your premise is that the power to control content lie with one particular interest group instead of another.
What's special about Twitter that they get to decide who can use their computers, routers, switches and so on, whereas level-3 is not allowed to do the same?
The physical medium is the limited public resource. We have all the public ground and all the radio spectrum we'll ever have. Tearing up roads, wiring up cities, assigning spectrum, blanketing the country in antennas, are national infrastructure projects that take decades and billions of dollars. In America with our belief in the free market we've traditionally done these projects with public/private partnership. But we can't give corporations complete free reign because they're using our one set of physical resources, if they screw those up then we lose access to our shared telecommunication infrastructure.
On top of these physical networks the digital companies are building virtual networks. Twitter, Snapchat, Medium, Google, Facebook, Apple, Microsoft, Amazon, and a thousand more companies vigorously competing in these virtual domains. The virtual worlds are so vast and we're still trying to understand their potential that even when these companies seem to be forming monopolistic locks we should give them free rein. You have more communication channels today then anybody else in human history. Stop calling for government control of our unlimited virtual resources.
What's special about Twitter that they get to decide who can use their computers, routers, switches and so on, whereas level-3 is not allowed to do the same?