[hga]

Sprint made it an integral part of their long distance adverting in the mid-80s: http://www.retroist.com/2014/11/18/sprints-pin-drop-commerci...

They also counter advertised against MCI, founded as Microwave Communications, Inc., on the basis of their using fiber and MCI still using a lot of microwave. From http://www.fundinguniverse.com/company-histories/sprint-corp... E.g.:

"In a spirited demonstration of the obsolescence of the microwave networks operated by AT&T and MCI, US Sprint blew up one of the last of its own microwave towers in February 1988."

I remember seeing a print add at the time with a picture of the controlled demolition in progress.