Much of the world already relies on nation-states for message delivery through the post office.
Because everyone utilises such systems, everyone has a vested interest in the privacy of such systems. Under liberal democratic governments, protections for privacy, security, and integrity are typically quite strong. Not inviolable, and you'll likewise find a significant set of criminal laws for crimes transacted utilising postal systems (mail and wire fraud, etc.), but specified and typically balanced.
Mind: that emerged over time, and a significant early interest of governements in operating messaging services was of course message intercepts.
That said, the early history of telegraphic and telephonic communications (both often privately owned and operated) is hardly much better. See the case of AT&T and the Republican Party swinging presidential elections, as told in Tim Wu's The Master Switch.
Because everyone utilises such systems, everyone has a vested interest in the privacy of such systems. Under liberal democratic governments, protections for privacy, security, and integrity are typically quite strong. Not inviolable, and you'll likewise find a significant set of criminal laws for crimes transacted utilising postal systems (mail and wire fraud, etc.), but specified and typically balanced.
Mind: that emerged over time, and a significant early interest of governements in operating messaging services was of course message intercepts.
That said, the early history of telegraphic and telephonic communications (both often privately owned and operated) is hardly much better. See the case of AT&T and the Republican Party swinging presidential elections, as told in Tim Wu's The Master Switch.