Legal and tax related matters are so complicated, it is hard to standardized through any technology. It is because the interpretation of a tax or legal term can be different based on the situations. I don't think any start up has tried or even interested to solve this kind of issues yet.
This is the case when there is no legal framework. For a law to be in place, the guide must be there and for cryptocurrency, the whole emergence is yet to be backed up legally. So whatever law or regulation, because it is not inscribed in the constitution might not see the light of the day especially because the court won't be able to lay reference to the constitution.