I've bought some chess books, and others I've downloaded. The reason why I did it was: because I couldn't find it, or was very difficult to find it, or I had no money to buy it. I asked myself if I was doing something bad but couldn't find an answer. I think that if I can buy it I would do it, because I'm old style and I really prefer the real books, and in case I cannot I can download it for free.
It's such a good feeling to have books and knowledge, ideas and explanations in front of you with a click, so I don't think it will be stopped easily this filesharing.
Regarding the earnings of the author there are two points to face. The first is if the author wants his book to be bought because he's greed more than in real need. The second if this downloading has a strong effect on his economical life, then in this case to download is ... not the best. I personally think that downloading is hated because of the greed of the authors and editors than for their real situation. But is my opinion, simply. It's like they stand against borrowing books from friends because you'll read it without paying.
I think that soon there will be a solution for all this: everything will be made online, and one day we will pay 2 dollars to download a book. It will be good for readers and for authors. One will have the knowledge and the other the 2 dollars. Otherwise nobody will have anything.
In Italy you can rent a book for free in public libraries. Everything is made with public money. Following the idea of my imagination we will have more taxes so our poors can download books for free and the country will pay the 2 dollars to authors. A futuristic welfare state! =)
As Kopimism is an official religion in Sweden, isn't this entire topic off limits? You are all debating whether or not adherents of Kopimism are allowed to practice their most holy sacrament of copying.