Somehow, not seeing the whole paradigm that Napster portended still haunts me. I stumbled (back) upon this after hearing a Grateful Dead iteration from years ago. Obviously, the genealogy of this song is something that precious Metallica didn't get. Now, more than ever, the Beavis and Butthead nod to these morons seems appropriate.
At least read the Wikipedia entry on "Whiskey in the Jar".