I didnt want to post this until later and in the other thread, but the cats out of the bag. If any of these stolen (supposedly) bitcoins hits any of the exchanges there will be a bank account associated with withdrawaler's exchange account. Lets hope for allinvain that an account has been associated with the mtgox account via Dwolla or what ever. But I doubt this has occured yet. Sense exchanges wants to maintain their legal reputation with governments they will comply with authorities requests regarding the laundering actions of moving the bitcoins on the exchange to another btc address. If merchants accept these btc and ship an item they will have a physical address. If something is shipped to someone and they keep the item they might be charged with receiving stolen goods.
So what does this leave? As I see it the deep underground is the only places to spend these btc. If these btc were really stolen they are basically worthless because the chain will lead back to the theif. Moving the btc between addresses is not affective laundering. There would need to be a way to move the btc into another wallet using a third parties address. Then again, I think the 'middleman' would comply with requests from athorities if they are a service provider or even if that service is a gambling site. The operators of SilkRoad will understand my meaning soon ehough.