In this file photo, Twitter CEO Dick Costolo attends a seminar during the 59th edition of the International festival of creativity in Cannes, France, on
In this file photo, Twitter CEO Dick Costolo attends a seminar during the 59th edition of the International festival of creativity in Cannes, France, on June 20, 2012. Twitter announced on Thursday through its own service that it has filed paperwork for a planned initial public offering of shares. (SEBASTIEN NOGIER/EPA)