At the time, the words were considered highly inappropriate and unsuitable for broadcast on the public airwaves in the United States, whether radio or television. As such, they were avoided in scripted material, and bleep censored in the rare cases in which they were used. Broadcast standards differ in different parts of the world, then and now, although most of the words on Carlin's original list remain taboo on American broadcast television. The list was not an official enumeration of forbidden words, but rather was compiled by Carlin. Nonetheless, a radio broadcast featuring these words led to a U.S. Supreme Court decision in FCC v. Pacifica Foundation that helped define the extent to which the federal government could regulate speech on broadcast television and radio in the United States.
During one of Lenny Bruce's performances in 1966, he said he was arrested for saying nine words, and says them in alphabetical order: ass, balls, cocksucker, cunt, fuck, motherfucker, piss, shit, tits. The last seven words are the same as George Carlin's.
In 1972, George Carlin released an album of stand-up comedy entitled Class Clown. One track on the album was "Seven Words You Can Never Say on Television," a monologue in which he identified these words, expressing amazement that these particular words could not be used, regardless of context.
I don't know that there was a 'Eureka!' moment or anything like that. On these other things, we get into the field of hypocrisy. Where you really cannot pin down what these rules they want to enforce are. It's just impossible to say 'this is a blanket rule:'. You'll see some newspapers print 'f blank blank k'. Some print 'f asterisk asterisk k'. Some blank-- Some put 'f blank blank blank'. Some put the word 'bleep'. Some put, um... 'expletive deleted'. So there's no... there's no real consistent standard. It's not a science. It's a notion that they have and it's superstitious. These words have no power. We give them this power by refusing to be free and easy with them. We give them great power over us. They really, in themselves, have no power. It's the thrust of the sentence that makes them either good or bad.