The number of infringement suits filed by NPEs controlled by inventor Leigh M. Rothschild sharply increased last year, with over 140 patent cases filed in 2015 compared to just 35 in 2014. In fact, according to RPX’s 2015 NPE Activity: Highlights report published on January 4, 2016, Rothschild ranked first among the top ten NPEs by campaign defendants added in 2015.