What were the hot topics for Data Center Knowledge readers during 2011? Readers are fascinated with the companies running the Internet's largest infrastructures - Google, Facebook, Apple, Microsoft and Amazon - and how operate their data centers. Also popular: coverage of supercomputers and data center cooling. What were the stories that held your attention this year? See the Top 10 Data Center Stories of 2011 for our rundown of the 10 most popular stories on DCK, ranked by the number of page views they received.