The broker reserves the right to remove the bonus without giving any notice ifa client misuses the given bonus. Some of the violation terms:
2.1 Using the bonus for hedging with our broker or another broker. Proving of hedging is an easy job by using some specific parameters, and it is not necessary to give the trader any explanation about it. If it is proved for the brokerage that a client used hedging methods, his trading account would be blocked.
2.2 The clients who use legal trading methods can easily use the bonus and therefore decrease the risk of trading. If a client has an open order, he can use 100% of his bonus. On the other hand, if a client has not an open order and used 80% of the bonus, the rest of the bonus will be removed from his account.
http://fxglory.com/articles/promotions.php