Well, for my country it is not illegal but I can say that if you make a high amount of bitcoin and than exchange it for fiat currency they may ask where did you get this money from which might be hard to explain to goverments all around the world. So make bitcoin, spend bitcoin 
,means do not try to encash it.
,means do not try to encash it.Why you want to go through all these trouble? Instead of receiving the money in your bank account, you can meet up with some reputed trader from the localbitcoins and then exchange your coins for physical cash. How the government is going to track you?