I was thinking about this the other day.
In Season 4 when Darryl, Tyreese, Michonne, and Bob make the supply run looking for antibiotics for the chicken flu, they heard some sort of really quick broadcast on the radio. We also see Terminus making a broadcast at the end of the season. Does anybody think they were the ones on the radio that was picked up or is that just coincidence and doesn't matter in the overall plot?