An anonymous reader writes: Former Uber CEO Travis Kalanick has absorbed blistering criticism for the way he handled allegations of sexual misconduct at the San Francisco riding-hailing service. But he can at least count on the support of one big name in Silicon Valley: former Yahoo CEO Marissa Mayer. Speaking at the annual Stanford Directors' College Tuesday, Mayer defended Kalanick, suggesting that he was unaware of the toxic culture brewing at Uber because of the company's rapid growth. Mayer's name has come up in reports as a possible replacement for Kalanick at Uber, though there's no indication the company has had talks with her. "Scale is incredibly tricky," Mayer said. "I count Travis as one of my friends. I think he's a phenomenal leader; Uber is ridiculously interesting. I just don't think he knew," she said. "When your company scales that quickly, it's hard." Mayer then compared Uber's situation to the early days of Google when it first brought in Eric Schmidt as CEO to help co-founders Sergey Brin and Larry Page manage the company.