But now, with MP3's, everything is suddenly possible. The problem is, it's getting harder and harder for any artists or labels to control the release of material anymore. Even if you sell the CD, nothing is stopping anyone from copying it. But, being late to the game, the big labels haven't yet figured out a way to get their cut of the music. They haven't been able to figure out how to plug the hole in the dike, either.
Unauthorized duplication is a violation of applicable laws.
You will find this quote on virtually every CD you buy. It means that the road tape you made for your car is illegal. It means the CD copy that you made of your wedding song is illegal. It means that the copy of the CD that you made for your friend could land you in jail. This includes any business with music in the waiting room or on the phone for customers while on hold.