I'd have to say All of the Above!
In reality, I doubt very much that musicians are losing much money. Most people do not want to go to the trouble of taking the time to download a few songs then put them on a CDR. It's cool when you have the equipment and the time, but otherwise, most people would much rather just go buy the CD. Now if someone or some album was just a one-hit-wonder anyhow, few people I know would actually go out and buy a hard to find CD just to hear "Mexican Radio" or "Take on Me" lol
On the other hand it's not totally unimaginable that some kid with a lot of time on his hands might make a profit (at very little loss to the artist) downloading his own version of a "Greatest Hits" CD, making tons of copies and selling them to friends.
As much as I love Metallica, I find it ironic that they became popular in large part due to bootlegging of their demo tapes. They were underground/word of mouth popular. Now that they have made their money, all of a sudden, it's time to screw everyone out of a major convenience because they might lose a few CD sales? What a shame.... Lars, you lunkhead....
Life is a succession of lessons which must be lived to be understood. - Helen Keller