The most prominent attempt to address ballooning intellectual property litigation took effect in 2012 and aimed to cut claims by patent owners that don't actually make anything. But it's had mixed results. "While the America Invents Act [Pub. L. 112-29] may have slowed the train somewhat for a time, it is still barreling down the tracks," says UC Hastings law school professor Robin Feldman, who directs the school's Institute for Innovation Law. To find trends, she reviewed all patent lawsuits filed in selected years between 2007 and 2012.