Well, there's that one alleged program with the name "Perfect Citizen" which seems to touch upon using the power grid as backbone SIGINT & data transport infrastructure:

https://yro.slashdot.org/story/12/12/23/2119225/nsa-targetin...

https://it.slashdot.org/story/10/07/08/1449254/us-plans-cybe...

These are dated as old as 2010-ish...