They don’t make anything. They don’t sell anything. But patent trolls earn upwards of $29 billion a year, and that’s not even taking into account hush-hush, off-the-record settlements. How do these trolls operate, and how are they damaging the economy as well as stifling innovation? Zach Weissmueller from Reason.TV probes the issue with an assist from Julie Samuels, an attorney and the Mark Cuban Chair to Eliminate Stupid Patents at the Electronic Frontier Foundation.