the dow down right now about 400 points and believe it or not, that is about 100 points better than it was an hour and some change ago. markets continuing to take a tumble. we'll keep following it for you. amid all this market turmoil, though, power brokers of the digital age are flouri flourishing. in tech circles they are known as the gang of four. google, facebook, apple, amazon.com, each of them a household name to american consumers, and they are all in the race to the top. but in an ever-changing world, who has the clout to be king of the mountain? a financial reporter for the "washington post" joining us this morning. what does each of the four have and what does each lack for total world domination? >> these companies are just impossible to escape at this point. every consumer deals with them so you've got google, world's most dominant search engine, and