Twitter’s Dick Costolo to Depart; Jack Dorsey Returns

San Jose Mercury News: The rumblings that Twitter investors were unhappy with CEO Dick Costolo’s performance rose to the surface Thursday, as the social network’s leader announced he will step down and cofounder Jack Dorsey will take over on an interim basis. “I am tremendously proud of the Twitter team and all that the team has accomplished together during my six years with the company,” Costolo said in an announcement. “We have great leaders who work well together and a clear strategy that informs our objectives and priorities.” Still, investors had grown disenchanted with Costolo as Twitter struggled to expand its user base beyond a hard-core group of fans. Critics said that Costolo had not settled on a direction for Twitter and adequately communicated it amid constant changes in the executive ranks of the company.