I can see burning CDs and selling them should be a crime --and the profits should be confiscated ---but as long as no money is exchanged then it's a different situation. You can find all kinds of cheap bootlegged CDs at any flea market around here ---if those guys can make a profit selling them then the music companies should be setting their prices accordingly. Free market competition.
If I burn a copy of one of my CD's and lend it to a friend, I can have some degree of confidence he's not going to burn more and sell them at flea markets. While it's possible I don't know my friends as well as I think I do, I don't lend music to people I think might do such a thing.
By contrast, if you put music on the Internet for promiscuous download, there is a fair likelihood that it may be downloaded by people without such scruples. If someone downloads a song you put on the Internet, burns some CD's, and sells them at a flea market, have you not contributed to their crime?