I do not know whether this is fraud or a violation of the tax codes, but you can ask the IRS by sending a letter to the following address to investigate it:
Department of the Treasury Internal Revenue Service MC 4910 DAL 1100 Commerce Street Dallas, TX 75242
I have suspected for sometime that the WTBTS holds conventions because they are money making events and not just to keep JWs busy and fed. I wrote my concerns to the Treasury Secretary and wrote about my letter in the thread http://www.jehovahs-witness.net/watchtower/scandals/225198/1/Will-the-IRS-Investigate-the-Watchtower-Society .
Peace be with you and everyone, who you love,
Robert