If bitcoin clients ever adopt the zerocoin protocol then there wouldn't be anything to track: http://zerocoin.org/ http://zerocoin.org/ Although they seem to

If bitcoin clients ever adopt the zerocoin protocol then there wouldn't be anything to track: http://zerocoin.org/ http://zerocoin.org/ Although they seem to think that the protocol should not allow anonymity for some transactions: http://zerocoin.org/q_and_a#what-about-money-laundering http://zerocoin.org/q_and_a#what-about-money-laundering