<Updated 2013-05-11> Recently Derek, a fellow Premier Field Engineer (PFE), had a customer request on how to remove duplicates from a SharePoint 2010 list. I have written some PowerShell scripts that remove list items, but never to check for duplicates. My main concern for this was performance as looping through a list searching for duplicates could be an expensive operation. Problem As it turns out the customer had a list with more than 85,000 items and many of the list items were duplicates. ......