Seem Panda is pro copied content ...
"As bloggers, we often refer to previous articles, and we have this habit of searching for an older post or checking on who is syndicating our content. After the second Panda update, we could not find many of our own posts with a search on the title or a specific phrase from the article. Instead, what we found was that sites that *steal* our content do rank higher in the Google search results, while our own post archive could not even be found. We immediately knew that something was very, very wrong.
If you have your own site, do this: copy the first line (or the title) of a post, and search for that phrase. If this phrase is unique enough, your article will appear first (if not, you will simply compete with others)"
"As bloggers, we often refer to previous articles, and we have this habit of searching for an older post or checking on who is syndicating our content. After the second Panda update, we could not find many of our own posts with a search on the title or a specific phrase from the article. Instead, what we found was that sites that *steal* our content do rank higher in the Google search results, while our own post archive could not even be found. We immediately knew that something was very, very wrong.
If you have your own site, do this: copy the first line (or the title) of a post, and search for that phrase. If this phrase is unique enough, your article will appear first (if not, you will simply compete with others)"