> Doesn't running a telephone network help people do the same?
They do, but they are not only share the metadata with law enforcement, but also let them wiretap. (Often they require a warrant for this, but that is not a hard burden for a LEO.) And this capability is not some aftertought, but deeply integrated into their tech stack.
> post office help people communicate coded messages about nefarious thing
The US postal service scans and stores the outside of every envelope and package they handle. Law enforcement agencies can query this metadata.
https://en.m.wikipedia.org/wiki/Mail_Isolation_Control_and_T...
> Doesn't running a telephone network help people do the same?
They do, but they are not only share the metadata with law enforcement, but also let them wiretap. (Often they require a warrant for this, but that is not a hard burden for a LEO.) And this capability is not some aftertought, but deeply integrated into their tech stack.