I have recently discovered that Google will index RSS feeds even if they are
not explicitly defined and submitted as sitemaps. All seemed benign, but it
turned out that duplicate URL's might be returned, e.g.
Will it not have a bad effect? Like that of a mirror or PageRank
unnecessarily distributed across more page? Note that the question mark is
appended to the original URL, but does not affect it. However, Google
returns results with the '?from_rss' included. Should this be a cause for
concern? Many news site use similar strategies, so can they be wrong?