Oskar Liivak. For some time patent law has been criticized for a flood of bad patents. Patents of questionable validity are being issued with overly broad, often nebulous boundaries. A majority of the blame for these bad patents has fallen on the shoulders of the Patent and Trademark Office (PTO). Bad patents exist, so the argument goes, because the PTO has improperly issued them. In response the PTO has launched a major initiative to improve patent quality. Our singular focus on the PTO though threatens to overlook the other major player responsible for patent quality—patent applicants. Currently patent applicants are not seen as having any particular duty to seek only good patents. Today applicants can seek excessively broad claims if they want to. It is the PTO’s job to police against such excessive claims. This article shows this practice of overclaiming is dangerously mistaken. Though not generally appreciated, the patent statute includes powerful features that put a significant duty on applicants and their patent attorneys to file only properly sized patent claims. As shown, applicants have a duty to file claims that do not exceed their invention. And though it likely comes as a surprise to much of the patent bar, that duty is enforced by criminal sanctions. Simply put, willful overclaiming is criminal; it is a felony.