I'm not quoting anyone on purpose, but what I want to say actually connects to a lot of posts that have been said.

While I agree with a lot of more "liberal" views on the issue, the best argument against file sharing connected with the music bussiness was on a alt-rock board. The guy said that he worked for the biz and that he buys every single rock album that he thinks is good. Why? Because every album he buys is a vote against bands like Nickleback and for good and small bands with creativity.
So he said that people who like Nickleback, GnR and such have less ideas about filesharing then people who listen to Tool and The mars volta (just examples). So more people download Tool albums, so the industry doesn't notice bands like them. So it is only logical that they support cash cows like Nickelback instead of supporting young creative bands, because it is exactly those bands that get mostly downloaded.

Now I am just playing the advocate off the devil and this is not my opinion. But I have to say that this was a good argument that let make me rethink quite a lot.

I always did buy the albums of my fav bands, btw.