Myhrvold’s firm illustrates in a way that no law review article could the extent to which the patent system punishes firms that actually produce useful products. Firms whose business models involve actual innovation have to show restraint in exploiting their patent portfolios. If they don’t, there’s a high probability that some of their adversaries will countersue and both firms will be dragged into a legal quagmire. But if litigation is your only business, then you’re not vulnerable to retaliatory infringement lawsuits, so you can exploit your patent portfolio much more aggressively. Many small “patent troll” firms have exploited this flaw in the past, but Myhrvold is the first person to recognize that it can be exploited in a systematic, large-scale fashion.