Mt. Gox customers with frozen bitcoin accounts are targeting founder Mark Karpeles, arguing in court papers that he is unfit to lead the Japanese bitcoin exchange through its U.S. bankruptcy case, the Wall Street Journal reported today. In bankruptcy court papers filed on Tuesday, lawyers for several Mt. Gox customers pointed out Karpeles has been accused of fraud and said that he should no longer have power over Mt. Gox's U.S. assets in his official role as Mt. Gox Co.'s foreign representative.