1971: Uniformed cops are generally known as 'wallopers', and cops in plain clothes are called 'demons'. These latter, supposed to be disguised, are instantly recognisable. — John O'Grady, Dealing with Cops, from Aussie Etiket, 1971. Quoted in Aussie Humour, Macmillan, 1988, ISBN 0-7251-0553-4, page 200.