Also no-one's doubting the sites' intentions, merely the effects.

Not true, Howard - I for one very much doubt the effects - and I also question the smugly superior tone of such posts as yours, especially such statements as:

To repeat it for the umpteenth time, copying an album for a mate is one thing, making it available for hundreds, perhaps thousands, to download is different.

Which is just hysterical theorising than runs contrary to the overall spirit of this thread. Otherwise, I agree with Sean's post entirely.