I think if darkcoin gets more well known regulaters might bann it
Have they really banned any coin so far? No they haven't. Also you can't really ban a specific coin, especially since it is trading mostly BTC/DRK.
They can target exchanges to delete the coin for example, that could be a start. So i would say don't get too greedy while you are in profit.
They can't depending on the country. Besides, any exchange removing DRK now would lose a lot of revenue. The volume in the past 24 hours is almost 4 million USD.