In an open letter to Tesla Inc.'s board of directors on Friday, a group of shareholders expressed their dismay with CEO Elon Musk, claiming he was being distracted by commitments to other ventures such as Twitter. "The Board has allowed the CEO to be overcommitted at a time when the company faces critical challenges, including increased competition, regulatory scrutiny, and a stock slide," the group wrote. The letter noted that the investors who signed the letter own $1.5 billion worth of Tesla shares, which make up well less than 1% of all Tesla shares. Follow benzinga . . . . . . . #twitter #elonmusk #tesla #xcorp #business #sanfrancisco #shareholders #musk #shares #stock