What stops one person trading with himself on two accounts on Gox? Passing a BTC from one to the other then privatly back to himself, or whatever. Such that there seemed to be a lot of trading occuring at a much higher price than the average, moving the average up without the trader gaining or loosing any money?
How do you tell who you are trading with? If you are using Gox as an exchange, you have no control who you buy/sell from/to.
If you are using Gox as a wallet provider, passing BTC from wallet to wallet does not constitute an exchange trade.