Management guru Sonnenfeld slams Facebook COO Sandberg, saying she 'probably should be replaced'
"Sandberg is completely dispensable," and should "probably should be replaced," Yale's Sonnenfeld says. Facebook co-founder and CEO Mark Zuckerberg "should no longer be chairman," he adds. Sonnenfeld's criticism comes after Sandberg's denial of a New York Times report that she ignored Russian activity on social network.