The legality of bitcoin depends on who you are, and what youre doing with it.
There are three main categories of bitcoin stakeholder. Someone may fall under more than one of these categories, and each category has its own legal considerations.
If fiat currency can be use by anyone by bad and good people then same with the Bitcoin currency in which it can be use by both good and bad people and both in legal and illegal acrivities too.The same currencies for spending with only the appearance is the difference but the good thing for Bitcoin is it can be regulated so that it can only be use in legal means. I just don't understand what are these 3 categories that are you talking about?