Unfortunately this guy is free to do what he wishes, as we all are.

This shows how ill prepared the market and ecosystem is for the growth of the past year. Rich people move and manipulate their money all the time, but we are on a public ledger and our money is also an investment/asset class. You and I can't legally and publicly access the bank accounts of billionares and follow it, but in bitcoin you can. Think of what would happen in traditional markets if you could follow the market makers accounts like this. I'm a big fan of a public and immutable ledger, we just are seeing right now how it can be used for manipulation in this infancy.
Big money man moves his digital money = everyone gets spooked. Realize the pattern = profit off of it, just as the rich and powerful have always done.

At the same time its very frustrating, especially given the player is tied to Mt. Gox of all parties. How much damage could one shitty exchange do to this space, we still await the final answer.