The purpose of patent system is to accelerate and contribute for the development of technology and industry by promoting and protecting invention and its use. But, the advent of software patent, especially business model patent, and the environment where technologies are connected with each other and too many patented technologies are involved in the development of a new product, are providing a very good play ground for patent trolls to extort large amount of damages from companies which manufacture and distribute products investing lots of resources. Patent misuse by patent trolls can result in stalling and discouraging the investment for new products, which can lead to the failure of the whole patent system. So, measures for protecting patents as well as preventing patent misuse should be considered. Patentees usually exercise their rights by seeking injunction or monetary damages, so proper exercise of their discretion by courts in issuing injunction and calculating damages is highly important for protecting patentee’s rights as well as deterring patent misuse. Courts should compare the benefits and damage for patentees and alleged infringers before issuing injunction. In that comparison, they should consider whether the related patent would be invalidated or the patentee is commercializing the patent. In regard to damages calculation, courts should keep in mind that Section 128 of Patent Act of Korea exists to prevent conferring excessive damages by setting the ceiling according to patentee’s production capacity as well as to make damages calculation easy and simple. So, courts should also consider patentee’s own intention and capability to reduce to practice the patented invention. Especially when the patented technology is related to the small portion of the infringing product, courts should consider how much the patented technology contributed in manufacturing and selling the product.