In 2011 the Leahy-Smith America Invents Act created three new
types of post-issuance proceedings to challenge patent validity:
inter partes review,1 post-grant review2 and
covered-business-method review.3 These proceedings have
proven to be popular avenues to challenge patent validity among
accused infringers and, correspondingly, unpopular among patent
holders.
The popularity of these proceedings among accused infringers can
be attributed to several factors: (1) the lower burden of proof
(preponderance of evidence) needed to prove invalidity, (2) the
higher success rates attributed to AIA proceedings, (3) the
relative speed of AIA proceedings and (4) the likelihood that
related litigation will be stayed.