or even patented before, ignoring material prior art, then even existing technologies in use are subject to patent trolling. Reexamination to invalidate the patent based on prior art can be requested, but requests are typically made only after a lawsuit is filed or threatened (about 0.33% of patents in U.S. have re-examination requested) and often in conjunction with an infringement lawsuit. Only the patent holder will participate in this process, and the party requesting the reexamination has no right of appeal and is estopped from using the same evidence in any subsequent civil action; this risk keeps the popularity of reexamination low despite its lower cost. Furthermore, the most common outcome is not the validation or invalidation of the patent, but narrowing the scope of the claims. There is also no obligation to defend an unused patent immediately, thus manufacturing companies may produce the patented product for years until the patent troll sues them. For example, the JPEG format, intended to be free of license fees, was subject to two patent attacks, one by Forgent Networks during 2002–2006 and another by Global Patent Holdings during 2007–2009. Both patents were eventually invalidated based on prior art, but before this, Forgent collected more than $100 million in license fees from 30 companies and sued 31 other companies Effects In 2011, United States business entities incurred $29 billion in direct costs because of patent trolls. Lawsuits brought by "patent assertion companies" made up 61% of all patent cases in 2012, according to the Santa Clara University School of Law. From 2009 through mid-2013, Apple Inc. was the defendant in 171 lawsuits brought by non-practicing entities (NPEs), followed by Hewlett-Packard (137), Samsung (133), AT&T (127), and Dell (122). Patent troll-instigated litigation, once mostly confined to large companies in patent-dependent industries such as pharmaceuticals, came to involve companies of all sizes in a wide variety of industries. In 2005, patent trolls sued 800 small firms (those with less than $100 million annual revenue), the number growing to nearly 2,900 such firms in 2011; the median defendant's annual revenue was $10.3 million. A July 2014 PricewaterhouseCoopers study concluded that non-practicing entities (NPEs) accounted for 67 percent of all patent lawsuits filed—up from 28 percent five years earlier—and though the median monetary award size has shrunk over time, the median number of awards to NPEs was three times higher than those of practicing companies. A 2014 study