Dick Costolo, Chief Executive Officer of Twitter, speaks on stage during the TechCrunch Disrupt SF 2013 technology conference in San Francisco, California September 9, 2013. REUTERS/Stephen Lam ... more 
Dick Costolo, Chief Executive Officer of Twitter, speaks on stage during the TechCrunch Disrupt SF 2013 technology conference in San Francisco, California September 9, 2013. REUTERS/Stephen Lam (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY) less 
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Reuters | Photo By STEPHEN LAM / REUTERS
Mon, Sep 9, 2013 4:03 PM EDT