Mark Pincus

Pincus, the CEO of Zynga, was an angel investor in Facebook, having put up $40,000 alongside investments by Peter Thiel and Reid Hoffman. He recently took some stock off the table -- to the tune of $38.9 million -- but he still owns 4.3 million Class B shares. And Pincus has been in a selling mood of late. He's being sued for selling shares of Zynga at $12 a share just before the stock started to tank. It wouldn't be surprising to see Pincus dump more Facebook stock, and fast.