Jack Dorsey has announced that he is re-taking the reins of the social network that he helped build. Dorsey had been the interim CEO since it was announced that previous CEO Dick Costolo was stepping down in June of this year. Twitter created a search committee after Costolo's departure that included former Twitter CEO, Evan Williams, to find a new boss. Turns out that the figure was there, all the time. In addition, Dorsey will remain as CEO of Square, the mobile-payments firm he founded when he left Twitter. This will be Dorsey's second term as CEO, the first abruptly ending in 2008 when he was replaced as CEO by Ev Williams.