Well the Zimmerman telegram went via the US embassy in Berlin. And apparently Wilson offered this route to communications as an aid to peace talks - the deal being all messages had to be un-coded. They persuaded the US ambassador to allow them to send that one in code, as it would have a tad embarrassing otherwise...
Which means most of their stuff was still going to have to go via radio. Or sent on the commercial networks using subterfuge.
Biting the hand that feeds IT
