If you've run a forum for any length of time, I'm sure you've had at least one visit to DaniWeb. They were crushed harder that I had realized by the Google update and came close to closing their doors.
This is an interesting chronicle on Google Webmaster Central of Dani's attempt to restore her site's traffic: http://www.google.com/support/forum/p/Webmasters/thread?tid=6546710fb55bd11b&hl=en
Its 8 pages long, but well worth reading.
At any rate, I kept coming back to RSS and how it can be hurting sites. I get why she didn't do away with RSS because she had users viewing site content with readers and wanted to maintain that.
But why provide RSS as a non-authorized URL?
A better solution would be to require logon authorization to view an RSS feed. You can already send a user/password in an ftp URL, why not for RSS? It seems like that would reduce the scrappers passing off content as their own.