Twitter CEO Dick Costolo (R) celebrates the Twitter IPO with Twitter founders Jack Dorsey (L), Biz Stone (2nd L) and Evan Williams on the floor of the New York Stock Exchange in New York, November 7, ... more 
Twitter CEO Dick Costolo (R) celebrates the Twitter IPO with Twitter founders Jack Dorsey (L), Biz Stone (2nd L) and Evan Williams on the floor of the New York Stock Exchange in New York, November 7, 2013. REUTERS/Brendan McDermid (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY) less 
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Reuters | Photo By BRENDAN MCDERMID / REUTERS
Thu, Nov 7, 2013 12:51 PM EST