those patents? darren gersh reports. it's a cold war thing. >> reporter: microsoft's growing patent arsenal is like an arms race. if you have enough missiles, any attack will result in mutually assured destruction. patents operate the same way. at some point, you really don't need any more weapons, because each side has so many weapons they can't really use them in a meaningful way. >> reporter: if a company like microsoft has more patents, it has more leverage, more ways to argue it's not using someone else's technology in its products. but there is some offense to the patent hunt, too. it's a way to gain ground on opponents in key markets like smart phones. force the other guy to license your technology and pay a high price for doing so. >> if you slice into the other guys profits enough, you either make his products less attractive or you make your >> reporter: microsoft snapped up patents from aol in mapping, social networking, content generation, and streaming and that ammunition...