Here's feminist magazine take on Sheryl Sandberg's union with billionaires: "there remains some uncertainty as to what the Giving Pledge actually gives".
"Earlier this year, we learned that the 85 wealthiest people have the same combined worth as the poorest 3.5 billion people — half the world’s population. But a few of these billionaires, most recently Sheryl Sandberg, are doing some redistributing of their own by signing the Giving Pledge, a commitment started by Warren Buffet and Bill and Melinda Gates to give away half their riches either during their lifetime or upon their death. For someone like Warren Buffett, this pledge would amount to a donation of over $29 billion. On Friday, Forbes reported that Sandberg and her husband Dave are two of the seven latest power players to sign the Giving Pledge — but there remains some uncertainty as to what the Giving Pledge actually gives." -- Lulu Chang, Bustle.com