By Jim Finkle and Karen Freifeld BOSTON/NEW YORK Thu Apr 3, 2014 6:58pm EDT (Reuters) – A number of U.S. states are jointly investigating a data breach involving a subsidiary of Experian Plc that exposed the social security numbers of some 200 million people to potential criminal activity. A Vietnamese man last month confessed in U.S. District Court in New Hampshire to orchestrating the breach, so the focus of the multistate investigation will likely be […]