Recently, Google and Microsoft jointly filed a lawsuit against GeoTag Inc. (a company that has filed at least 397 lawsuits regarding a GPS-related patent). The two large companies filed the lawsuit in order to invalidate the patent since the said patent had prior art that would allow to be used by companies without having to pay royalty fees.
Although it may seem that these two companies filed the lawsuit to protect their own interests, it should be noted that the defendant in the lawsuit appears to be claiming royalty fees from the patent in order to fund for their own release of a GPS-related service.
Patent trolls have always held back the improvement of technology by filing ideas that they have no intention of bringing into market. In order to prevent this kind of abuse, companies that file patents should market products using the patent or risk losing the right to owning the patent in a set amount of time.