Read up on BGP. I'm sure the government has a lot more control over infrastructure in other countries, but in the US, it's all privately owned. Perhaps some lease pole space from local or state governments. Our network never leaves my state, at least for now, so I'm unsure of the politics involved in crossing state lines. We pay for transport to a datacenter where we peer with other providers to connect out to the rest of the world. There are Tier 1 transports, the companies that own fiber traversing the globe. You peer with them. You can also peer at "meet-me" points, with other companies that have services in the datacenter. Big datacenters have hardware of all the big companies in them. It saves on transport costs to do this. A private company owns the building that is the datacenter. It's several floors. Very secure. Probably the most secure building in my state, but most don't know about it. This company owns several such buildings across the US. Possibly the globe. Haven't read too much up on them. Besides the state and federal government having servers and routers in there, I don't think they have much control over the building. I'm sure there's some secret room where they're sniffing every packet. Who knows. We rarely interact with the government. Just the occasional warrant for IP information.