Google (Nasdaq: GOOG) insiders have sold shares every month for more than three years. Amazon's (Nasdaq: AMZN) CEO and Apple's (Nasdaq: AAPL) CFO have recently sold shares of their companies. So how much should insider buying and selling matter to investors? Senior analyst Bill Mann gives his take on the Bear Stearns (NYSE: BSC) executive who sold it all, the Crocs (Nasdaq: CROX) director who recently loaded up, and the rationale behind the Netflix (Nasdaq: NFLX) CEO's pre-arranged plan to sell shares of his company.