infringers without practising or commercialising the technology covered by the patents they hold. NPEs are very effective in their litigations. Damages awards for NPEs almost are 3 times greater than practicing entities over the last 5 years. NPE lawsuits are associated with half a trillion USD of lost wealth to defendants, mostly technology companies, from 1990 through 2010. These lawsuits substantially reduce technology developers' incentives to innovate. Disproportionately harms startups Patent assertion entities (patent trolls) disproportionately affect startups, which are important for job creation and innovation. Companies with less than $100M annual revenue represent two-thirds of unique defendants in troll suits. A large percentage of startups reported that being sued by trolls resulted in significant operational impact. U.S. Supreme Court decisions Several Supreme Court decisions since 2000, as well as the Federal Circuit and district court decisions interpreting and implementing them, have dramatically impacted the status of software patents in the United States. They have particularly affected many thousands of business-method patents that issued as a result of Federal Circuit decisions in the 1990s. The two principal Supreme Court decisions were Bilski v. Kappos and Alice v. CLS Bank, the latter of which confirmed the applicability of the earlier decision Mayo v. Prometheus to computer-related inventions in which a computer was used to implement an abstract principle or preexisting business practice. (These cases are the subject of separate Wikipedia articles, which discuss the background and rulings in these cases in more detail, and supply authorities supporting the generalizations about those cases that follow. Additional detail is found in the Wikipedia article Software patents under United States patent law, along with supporting citations not repeated in this summary of those articles.) Bilski case The Bilski case involved a patent application on methods for hedging against commodity price fluctuations, which the PTO had rejected. The Federal Circuit, in In re Bilski, upheld the PTO's rejection on the grounds that the claims failed the machine-or-transformation test, which the court held should be used as the sole test of patent eligibility. The court did not hold that all business methods are patent ineligible, though a minority of the judges would have ruled that business methods are not properly the subject of patents. The Supreme Court affirmed the judgment of ineligibility, in Bilski v. Kappos, but on more general, and less articulated in detail, grounds of undue abstractness. It rejected the Federal Circuit's elevation of