"Moreover, this new definition would now include many corporations, such as IBM, which collect patents, not for manufacturing purposes, but to use them as a shield against patent infringement lawsuits. (Coincidentally, two commentators to my prior post on incremental invention mentioned IBM's practice of hoarding patents.) In sum, IBM, which has long been one of the largest owners of patents in the country, uses patents defensively. Its policy has been one of “mutually assured destruction,” i.e., if someone threatens to sue it for patent infringement, then it promises that it can find a patent in its massive patent portfolio with which to countersue for infringement. This policy has worked marvelously well for IBM, which has mostly avoided patent infringement lawsuits and has been left free to devote its time, energy and money to developing new products and services that it offers in the marketplace. But IBM's policy of hoarding patents is certainly "patent troll"-like behavior — patents are being used solely for litigation purposes and not for development of actual products sold in the marketplace."