File sharing. At some point or another, i'm sure we've indulged in it. Either through Napster (when is was still around), to Grokster, to Morpheus or Kazaa.
But how many of us understand the technology that powers these P2P (peer-to-peer) applications? Find out "what makes them tick":http://writ.news.findlaw.com/commentary/20030508_sprigman.html, and why copyright laws are finding it so hard to stick on them.