why bitcoin is still illegal in many countries of world 
Is there any solid reason behind this ??/
The reason behind this is they don't want their economics will be encountered with bitcoin , goverments wanting to banned bitcoin for life because they believed that this coin will scam people in the end. Also goverments don't want other currency to be use on their countries. Is there any solid reason behind this ??/maybe its because bitcoin is not accepted by many country, i think the other reason is the government can not make profit for using bitcoin and if they want to get profit, they should make regulation for accepting bitcoin and they should make their currencies so they can push people to using their currency too.