The George Carlin 7 words bit is one of the most famous routines in the history of comedy. Back when this came out in 1972, the media was slightly different than it is now. The censors in TV and movies had more control and they knew there were certain things that shouldn't be said on TV. This was the ultimate f you to the establishment because this list of seven filthy words you can't say on TV isn't about actually saying the words on TV. He's not trying to say them, but he's just looking at how ridiculous it is that you can't say these on TV. Who gets to choose which words cross the line and which ones, which mean the same thing, are OK, and which ones aren't OK. If you've never heard the George Carlin 7 words bit, you should listen to it right now.
The famous George Carlin 7 words list is: shit, piss, fuck, cunt, cocksucker, motherfucker and tits.
But during this George Carlin 7 words list he talks about how he got a call from an English linguist who said that motherfucker was a derivative of fuck, so he had to strike that from the list. But to George it still didn't feel right.
What's amazing is that George Carlin performed his list of the seven dirty words onstage at Milwaukee's Summerfest and was arrested for disturbing the peace. Kind of amazing that someone could get arrested for doing a bit on how language is so subjective.