Creditors of failed Bitcoin exchange Mt. Gox are trying to force its CEO Mark Karpeles to go to the U.S. for questioning related to a fraud lawsuit. Gregory Greene and Joseph Lack asked a U.S. judge to order Karpeles to go to the U.S. for a deposition, according to a motion filed Tuesday in U.S. Bankruptcy Court for the Northern District of Texas, Dallas division, which granted the exchange temporary protection from creditors.