Drupal's default RSS feed is bizarrely difficult to tame. There are a few issues with it, but the biggest one is the fact that each item's description has a link to the author's user profile appended to it in such a way that it can't be removed by any normal means—since user profile pages are not public for the vast majority of Drupal sites I build, this means there's effectively a link to a 403 error page in each RSS item.