One of the oldest (and most common) justifications for software piracy was “We’re just taking a little from a massive corporation.” They didn’t see it as directly affecting anyone. Or in the real world, many people have shoplifted something in thier life – but would never consider taking the same thing directly from a friend.
Mike Stackpole (among others) uses “moral DRM” to remind readers of this relationship – telling people that a real person is at the other end, and stealing the work directly hurts a real individual.
I think this also explains the effect that piracy has on sales for midlist authors and musicians. Part of the effect is due to increased publicity – if you don’t know that I write, how can you buy my work? – but another part is the awareness that you’re not supporting your band / team / friends. To make up for it, you go and buy more of thier work – both because you like it and to atone for stealing it earlier.
So that’s one factor – and one you might have heard mentioned before. But there’s one other way to minimize the effect pirates have on your work – and one I’ve not seen mentioned before. Look for the subject line “Drowning Pirates With Goodness”.