The Exchange: With nearly a billion users worldwide, Facebook (FB) is one of the hottest sites on the Internet and a defining force in online media.

But since going public on May 17, the ever popular social network has started to show a few kinks in its digital armor. First the stock price tanked. Then its domestic user growth slowed. And of course privacy concerns and data security remain ongoing issues for the company as it expands globally. (Facebook, Services, Web)