I ran into Kathy Lien and Boris Schlossberg (sp?) of dailyfx.com and FXCM this weekend at an invesment seminar. I was trying to get Kathy's take on longterm success of carry trading using correlated pairs. They both, of their own accord, warned me to stay away from operations arbitrage as they called it - e.g. long AUDJPY on oanda and short AUDJPY in an interest free account at FXCM. They told me that FXCM looks for accounts that lay dormant with no trades for a month or more and will shut these accounts down. It may have been an idle threat -- but certainly FXCM is not oblivious to "operations arbitrage".