I think I have answered this before in another thread. (not with binaries though)
They will restrict your bet size, offer you inferior prices, remove your internet access (make you phone in your trades) If that does not put you off, they will send you a nice letter saying that the directors of the firm have decided that they can no longer take your business.
Their pricing was poor initially, i.e. their vol estmates were useless.
They soon figured that one out! They force you to brake up larger orders, anything in size will get rejected and you'll have to call in (price will have moved, of this you can be sure)