Facebook has taken the unusual step of directly responding to a former employee who recently excoriated the biggest social networks for “ripping apart the social fabric of how society works.” And the company’s retort might surprise some people. Facebook isn’t outright dismissing or rejecting the claims of Chamath Palihapitiya, its former vice president of user growth. Instead, the underlining message seems to be that the Facebook of today is a far cry from the company he once worked for, and his perceptions are out-of-date.