The idea that the word 'phony' has its roots in the unreliability of the phone system is cute, but seems to be disputed by some dictionaries. The Oxford English dictionary says that the origin is unknown, but the American Heritage dictionary suggests that the word stems from an alteration of an old Gaeolic word fáinne, which was apparently pronounced as 'fawney' and referred to "a gilt brass ring used by swindlers." More info: http://www.word-detective.com/back-d2.html