Challenges to issued U.S. patents have grown at an alarming rate since the advent of inter partes review (IPR) on September 16, 2012. IPR is a procedure introduced under the America Invents Act that allows for challenging the validity of an issued patent in the Patent Office rather than in the courts.
One of the driving forces behind the popularity of the new procedure is that the implementing rules require the Patent Trial and Appeal Board (PTAB) to use the "broadest reasonable construction in light of the specification of the patent" when evaluating patents whose validity is challenged. By construing the patent claims more broadly than is practiced in a district court, the PTAB makes the patent claims more likely to read on the teachings of prior art references. The result? Claims are more likely to succumb to an anticipation or obviousness challenge.