If it's US cash it's safe. Non-US currency that can be shut down by the US without major penalty to the US is not safe. Even a small proportion of illicit trans

If it's US cash it's safe. Non-US currency that can be shut down by the US without major penalty to the US is not safe. Even a small proportion of illicit transactions will suffice for pretext. Bitcoin's best bet is to become widely used as quickly as possible. At this point it could be shut down (indirectly) with the vast majority of the public believing that was needed to stop the bad guys.