The phone analogy is terrible because the vitriol doesn't prevail. You aren't bombarded with 100 people's bigotry every time you pick up the phone.
Postal service is more akin to the infrastructure of radio/TV/newspaper (which differs, and is rather not one but various, e.g. cable, FM, and paperboys).
The analogy with Internet would be transit providers. The undersea cables between US and EU, for example. These are heavily logged, e.g. by UK. Imagine all your post be scanned, that'd be GDR-esque.