A Chicago attorney could face formal discipline from the Attorney Registration & Disciplinary Commission over claims that he disclosed confidential information in two cases and filed frivolous pleadings containing unsubstantiated accusations against opposing counsel and a plaintiff’s expert.Sole practitioner Joel A. Brodsky’s conduct in U.S. District Court in Chicago resulted in a sanctions order against him for $50,000 that was granted earlier this year by Judge Virginia M. Kendall. Kendall’s …