"Back in 2012, Congress reformed intellectual property law to protect tech companies from patent holders that don't seek to make or sell anything, preferring to pursue a strategy of stockpiling patents and suing productive manufacturers for alleged violations. Often trolls seek monetary settlements—a form of perfectly legal extortion—in exchange for dropping patent challenges and returning to their troll lodge."
"Egged on by Silicon Valley, lawmakers in Congress "fixed" the problem by creating a streamlined procedure by which tech companies could preemptively knock out questionable patents and thereby defuse the entire troll gambit. As so often happens, however, the 2012 reform had unintended consequences. Hedge funds began using the accelerated challenge procedure, known as inter partes review, to attack pharmaceutical patents while shorting manufacturers' stock—a way of betting that shares will decline."
From http://ow.ly/RmcOx :
Why This Small Victory Against Short Sellers Might Be a Big Deal for Biotech Companies
A 2012 reform meant to block patent trolls has opened drug makers to attacks by hedge funds