T-Mobile didn’t want its rural users to know how shitty its service was, so when the company couldn’t connect a call, it would play fake “ring tones” to the caller that made it sounds like the person on the other end wasn’t picking up. It did this “hundreds of millions of times” per year.

from Boing Boing https://boingboing.net/2018/04/17/local-ring-back-tone.html