If their country bans it then they need to stop or find away to keep their transaction hidden from anything that could lead back to them.
Surely there are plenty of ways but I don't think that everyone would take the risk and break the law .
So the market would surely be moved a little because of it.
Very few people would actually get scared of such a law which most likely will never be implemented in my opinion. Unless you submit your KYC to websites like LocalBitcoins and other exchanges, they will never be able to trace you.
This is the beauty of the crypto world. You can anonymously conduct your financial transactions without following any complicated protocols.