I imagine swear words are material to cases quite often, especially in defamation or employment cases (the latter being the first time I had to put one in a brief).  But I suspect they are rarely the focus that they will be in oral argument in this case before SCOTUS.  Apparently, “Justice Roberts is undecided on whether or not he should even allow the lawyers to use the words — and if so, whether to allow the argument’s audio to be played on C-SPAN.”