Is Napster Too Invasive?

Kyle Thomson asks: "I just left a Q&A with Hank Barry, C.E.O. of Napster (at University of Michigan). At the end, in a personal Q&A, he said that the banning of people was up to the artists, and that Napster fully complied with all requests. I then questioned him on the quick and easy ability to rejoin Napster. He said that 'the new version of Napster sprinkles bits around the hard drive. The only way to get back on is to buy a new computer.' So that leads me to the question of how invasive is Napster if it is leaving information everywhere on a hard drive?" What exactly does "sprinkling bits around the hard drive" really entail. I can see how this could mean "sprinkling random keys in your registry" but I admit to being a bit concerned by the actual description. Can anyone shed some light on this mechanism? Is it really as invasive as it sounds?