An article about what the recording industry is doing to try and stop pirating of music with review copies of songs:

Epic Records Takes Steps to Seal Its Newest Music. The Epic Records Group, a unit of Sony Music, is approaching the sticky problem of prerelease music's being traded online with an even stickier solution. By Chris Nelson. [New York Times: Technology]

Why don't they just go lotech like tapes. People still might bootleg it, but it's not quite as easy to make an mp3 from a tape as it is from a CD. You might still get some people doing it, but I bet you'd cut down on a significant portion.