It has its origins in WWII radar counter-measures - bogus targets dropped by aircraft to confound enemy surveillance.
"Who's the Chaff in this group? Look around, if you can't pick him out, it's you!"
Display a very limited vocabulary using words such as 'ravin' 'shafe geez' and 'give me your mobile or i'll f***king knife ya'
"Well, that figures--McCain is a military pilot after all."