Twitter CEO Dick Costolo (L) and Twitter co-founder Jack Dorsey walk the floor of the New York Stock Exchange during Twitter's IPO in New York, November 7, 2013. REUTERS/Lucas Jackson (UNITED STATES -... more 
Twitter CEO Dick Costolo (L) and Twitter co-founder Jack Dorsey walk the floor of the New York Stock Exchange during Twitter's IPO in New York, November 7, 2013. REUTERS/Lucas Jackson (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY) less 
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Reuters | Photo By LUCAS JACKSON / REUTERS
Thu, Nov 7, 2013 11:52 AM EST