Assuming someone decides to dump 18M ETH, or any other huge amount of coins, it's reasonable to assume that the coins should not be stored in the exchange for too long before the sell.
With transactions being transparent, could it not be possible to monitor ledgers for huge deposits and act accordingly, i.e. sell your coins quickly?
And if so, how difficult is it to automate that kind of monitoring?
That's not possible mate, but actually there is a news that US seems to want crypto currency enter the real world, but it will be through a regulatory board. Not a good plan for them, Im sure it will not push through as the crypto world don't bother themselves to be legalized already since it is already embraced by too many people worldwide.