A former Facebook executive is making waves after he spoke out about his "tremendous guilt" over growing the social network, which he feels has eroded "the core foundations of how people behave by and between each other." Chamath Palihapitiya began working for Facebook in 2007 and left in 2011 as its vice president for user growth. When he started, he said, there was not much thought given to the long-term negative consequences of developing such a platform. "I think in the back, deep, deep recesses of our minds, we kind of knew something bad could happen," said Palihapitiya, 41. "But I think the way we defined it was not like this." That changed as Facebook's popularity exploded, he said.