It's pretty obvious these networks didin't have an overall good use. As ruled in the betamax case, something with an overall good use to the people/economy/corporations would overshadow it's illegal uses. The reason IRC and Bit Torrent will live is because of this ruleing, however, the ruleing by the court against Grokster would prove to be a stepping stone to making the betamax case obsolete.
What I find funny, is without the betamax case, movie studios wouldn't be where they are today. Without the VCR mass production of movies would have never taken place. It's pretty sad that those same companys want to rule this out now.