People can easily circumvent this by creating new addresses. That simple. Also, given the whole address space of bitcoin is 2^160, that's literally inexhaustible and no amount of law enforcement can ever comprehend just how many that number is really in the real world. While measures would surely be put into place to combat money laundering and fraud in the space, I think it would not extend more than that since it's practically impossible to contain bitcoin and its working parts individually or as a whole. Bitcoin is, by design, fragmented and decentralized so as to avoid being manipulated and controlled by a central entity, and I think it has the capabilities to live true of its design.