Can Bitcoin be ban?
I don't think so. Though Bitcoin can't be regulated so that Bitcoin can't be banned also. Bitcoin is the unique system which is made up totally by software application so that Bitcoin can't be regulated. in the meanwhile, Bitcoin transaction could be banned in some area if a particular country wants to ban it.
So the transaction can be cotrolled but the total system couldn't be regulated or banned. for example, China has banned Bitcoin transaction in recent time but they are looking forward to getting free in the coming month.