Of course it's theorising, in the absence of statistics it's difficult to know the actual impact. But it seems probable that if something is available to the wide world then more copies will be made than if it's just left to people passing around copies between friends. It seems to me to be equally "hysterical theorising" to assume that music sharing is benefiting musicians by making them more widely known.

It's one thing for a well-known band to shrug their shoulders and accept downloads as free publicity to attract people to live gigs. For most folk artists that's not really a solution. Despite all the protests from music sharers that they're really doing musicians a favour, it's noticeable that it's the musicians themselves, to whom every CD sale is significant, who are objecting.

I'll say it again, if you want to discover new music then most musicians have examples freely available on the internet - on their own websites, Myspace or Youtube. It's not necessary to download a pirated album.