No, tape recorders are not part of the normal operation of phone networks.<p>The point is that even if a user intends to have an ephemeral conversation over an internet service all kind of middle-boxes may keep more persistent copies.<p>Something that normally does not happen with either face to face or telephone conversations.<p>With unencrypted digital communication on the other hand <i>past</i> conversations can be dredged up from all kinds of places.<p>End-to-end encryption basically abstracts ephemeral communication over channels with some sort of persistence.