if someone takes money out of my pocket, it hurts.
What matters is how the artist is affected.
Case A: 10 people buy your CD at $10. You make $100. But someone releases the mp3s and 20 people download it for nothing, and don't buy the CD. You make $100 and 20 more people have the music for nothing. That sucks. But they wouldn't have bought it anyway (they wouldn't have even heard it), so no one "took money out of your pocket" since no money minus no money plus no damn money is nothing. Did it hurt the artist? Not monetarily. It's illegal though.
Case B: the same 10 people buy your CD at $10. You make $100. But someone releases the mp3s and 20 people download it, and through word of mouth 5 more people buy your CD at $10. So you make $50 more, and 15 people got something for nothing. Did it hurt the artist? Quite the opposite, precisely because piracy caused the CD to reach a wider audience. $100 + nothing from 15 people + $50 = $150. And now 30 people have heard your music, so instead of having the 10 guys who bought your CD come to your show, you have 15 plus maybe a freeloader or two who liked the music.
You imagine Case A or something worse (what if no one buys the CD?). What studies purport to show is that piracy might often be more like Case B. I've heard the rumor that Microsoft is soft on Windows piracy because it helps keep their market share dominant! What's good is what helps the artist. And whether piracy is harmful to the artist is an open, empirical question that cannot be answered with a stomp of the foot.
Roger McGuinn testified before the Senate in 2000 that The Byrds never saw a dime of royalty money for "Turn, Turn, Turn" and "Mr. Tambourine Man". Pirating those records doesn't "take money out of Roger's pocket", because buying them doesn't put any money in.
Who piracy hurts and when is an extremely complicated issue. Some piracy is dead wrong, some of it seems to help artists, and some of it seems to be in between. I'm not trying to sell you on the idea that up is down. It's an extremely thorny issue, and as with all thorny issues, gut reactions and simplistic arguments are almost always worthless.

