Perhaps the uploader wanted to prevent the document from being pirated?
Google says RR Donnelley filed draft earnings statement without authorisation
http://uk.reuters.com/article/2012/10/18/uk-google-statement-idUKBRE89H17Q20121018
Google Blames RR Donnelley for Premature Earnings Release
http://www.businessweek.com/news/2012-10-18/google-blames-r-dot-r-dot-donnelly-for-early-earnings-statement-release
