It's becoming apparent that many large tech companies were government-backed entities and their success was fueled by public money. Where else did they get the rights to do this kind of stuff? Surely the public owns these cables as they are built in public waters.
Does the government own your car cause you drive on public roads? It is possible to build on public land if pay the government land rent, the government doesn't own the building and isn't involved in funding.
Also, international waters outside of the boundaries of countries aren't owned by anyone. They probably should be owned by UN to help with problems like overfishing.