But wouldn't those bit coins have to have come from some initial transaction? Say for example:
- I use bitinstant buy some btc to put into my wallet by depositing cash through bank wire or whatever.
- Then lets say I spend those coins on a a product that is banned in my country, and some gov. agent recieves my btc and confiscates it.
 without knowing my identity, but looking in the bitcoin network, couldn't he ascertain that I had previously placed money from bitinstance into my wallet (assuming he know's bitinstants wallet address, order on bitinstant raid, get logs/interview, and identify my bank wire)? or if not bitinstant, find anyone in my transaction history whose wallet is known and get them to disclose (potentially) identifying information about me?