Uber's head of communications Rachel Whetstone has become the latest high-level executive to leave the company. Neither she nor Uber has explained the move, but Kalanick's internal e-mail announcing the news was cordial, as were Whetstone's comments in a statement provided to CNN by Uber. Whetstone has been a key part of the aggressive lobbying machine behind Uber that has seemed to lose its way recently as cities and taxi industries across the world have pushed back against it in recent months. Whetstone had been prominent in Uber's response to the sexual harassment scandal that erupted after an ex-employee's viral blog post, but Uber's apparently limitless appetite for controversy and its insouciance about the concerns of others would overwhelm most mortal PR experts. Whetstone will be succeeded by her deputy Jill Hazelbaker. Fortune