An Aussie version of the same story posted by Captainsmiffy-
About 20 something years ago a sector north of Melbourne was being worked at night by a Flight Service Officer (a sort of poor man's air traffic controller using procedural separation before there was decent radar coverage)
Unidentified aircraft: "Jeez I'm f***ing bored!"
The FSO operating the sector, who was probaby a bit bored himself, nevertheless felt it was his duty to protect the airways so he called up individually each of the aircraft known to be in the sector:
Melbourne: "ABC, did you make an obsene transmission?"
ABC: "Negative"
Melbourne: "DEF, did you make an obsene transmission?"
DEF: "Negative"
And so on until all aircraft had responded.
Silence on the frequency until a few minutes later comes a transmission:
"Jeez I wan't that f***ing bored"