Now FM's right when he says that theft (or, in this case, making use of someone else's work without recompense) is wrong even if the person affected is rich. But for the sake of argument, say I'm a sound editor who makes 35K a year making the music you like sound good. I'm not the artist, I'm not the publisher, but my work is integral to the quality of the end product that you enjoy. How do you justify not paying me for my work? I need to pay rent, eat, save, etc. just as much as anyone else.
The only answer that I can come up with is that it's easy and you're unlikely to get caught. And, like FM says, that there's almost zero chance you'll ever have to look me in the face and explain your behavior. That's a pretty cowardly argument. No amount of rationalization will change that.