This telephone is bugged!

Anyone who came of age in the pre-mobile era will no doubt remember fondly the cheery bright-red (British) phone boxes, and rather less fondly the perma-film of grime on the receiver:

"In March 1908, a correspondent reported on a wide variety of London booths in which ‘the condition of the apparatus was unsatisfactory, the vulcanite mouthpieces frequently containing debris with a more or less bad odour.’ In June, Dr Francis Allan, a medical officer of the City of Westminster, reported the results of tests done on swabs taken from the mouthpieces of transmitters in public call boxes. One had attached to it a ‘mass of whitish-grey viscid substance’. The viscid substance was injected into two guinea pigs; one died after 23 days, the other after 27."

From David Trotter's piece in the London Review of Books, Vol. 32 No. 2 · 28 January 2010 (my italics)