Another related case was in the mid 2000s where someone did the same thing to Vodafone’s mobile network: https://en.wikipedia.org/wiki/Greek_wiretapping_case_2004%E2...
Circumstantial evidence suggests it was the US in that case.
The disturbing revelation here is that it sounds like the federal government has direct backdoor access to all these records without having to show any warrants.
This is since a looong time. HTTPS does not offers any security. It just serves to identify you in case they want to.