paxx,
Yes, I have downloaded MP3s off the 'net. But you know what? If I really like the music, I THEN go out and buy the CD. If I don't, well, guess what - since I don't like it, I'm not going to listen to it, and so I delete it off my machine - no sense in having something I'll never listen to take up space on my hard drive.
The same with copied tapes or burned CDs. Often I'll have a friend burn or tape something for me, so that I can see if I like it. If I do like it, 99% of the time I'll go out and buy the CD in question.
I like to 'try before I buy', and this allows me to do so.
Similarly, I used the shareware version of WindowBlinds for a good six months before buying the program. I needed to have time to try it out, and use it, before I actually spent money on it. Once I decided that I liked it, and that it was going to stay on my computer, I bought it.
Most people I know use downloaded MP3s in the same way that I do - to try out music before spending $20 or so on a CD. I only know of one person who just downloads stuff with no intention of ever paying for it.