Given their explanation of the law, I assume others will soon follow suit. I can't imagine too many exchanges will want to have physical currency deposited in Hawaii to match every Hawaiian customer's coinage. 
They wrote it was their interpretation of a law. This usually means people who not elected, but work in government, spent time and came to a conclusion. The blog post, when on to state, "... Coinbase is currently licensed to engage in money transmission in thirty-eight U.S. jurisdictions ..."
Once you are given something, it is generally very difficult to take back.
I was asleep for that one 
looks like all those "bad" miners still able to find blocks 
