Despite its high profile in the tech world, patent trolling — in which companies sue for damages over patents they dont intend to use — has been difficult to address. Reform efforts in Congress stalled earlier this year, when Sen. Patrick Leahy (D-VT) failed to broker an agreement that would have raised the bar for sending patent infringement warnings and increased the risks for bringing a frivolous lawsuit. In the wake of this defeat, Google, DropBox, Canon, and others are forging a truce that they hope will stop trolls from building a patent arsenal. Google calls it arms control for patents