I have never downloaded illegally, don't intend to start, and am not encouraging anyone to break the law. Having said that, as a songwriter/busker I see file sharing as beneficial: a way to publish and promote oneself inexpensively and efficiently, providing better opportunity to pursue a career free of outside control.

Traditionally, record companies and music publishers have held all the marbles, and have been able to abuse artists at will because of it. File sharing deconstructs that monopoly, which would explain why recording industry executives are leading the charge against it.

For songwriters who are not performers, file sharing threatens to dilute royalty income. But nothing prevents songwriters from striking deals directly with performers - except maybe publishers and record companies.
So, all things considered, file sharing adversely affects very few people, the majority of whom might be considered parasites anyway, and the remainder of whom might be better off sans RIAA.

If you're just going to fan the flame, piss on it!