A 2011 law made it easier to challenge Apple’s patents by Philip Elmer-DeWitt @FortuneMagazine December 20, 2012, 12:55 PM EST E-mail Tweet Facebook Google Plus Linkedin Share icons Samsung’s court filing. FORTUNE — On Wednesday, Samsung informed a federal court — and the Wall Street Journal dutifully reported — that the U.S. Patent Office had “rejected” all claims of an Apple AAPL patent (the so-called “pinch to zoom” patent, or ‘915) that the Journal described as “a cornerstone of its case against Samsung.” In October, the Patent and Trademark Office tentatively concluded that all 20 claims of another Apple patent (‘381) — the so-called “rubber-banding” (or over-scroll bounce) patent — were invalid. Two weeks ago, the office tentatively invalidated the broader “touchscreen heuristics” patent (‘949, A.K.A. the Steve Jobs patent). From the headlines, you’d think that the foundations on which a jury awarded Apple $1.05 billion last August were crumbling. The truth is a little more complicated. All three rulings flow from changes in U.S. patent law that Congress passed last year as part of the Leahy-Smith American Invents Act. Key provisions of that act make it substantially easier to challenge a patent after it has been approved. For a filing fee of $17,750, anybody can anonymously demand that the Patent Office initiate a post-grant review on any invalidity ground — including, according to the National Law Review, “prior art, lack of written description, or lack of enablement, but not failure to comply with the best mode requirement.” The new law makes it harder for the Patent Office to deny the review. Or, to put it the other way, easier to initiate a review — which is what has happened in the case of all three patents. A patent examiner agreed to take another look at Apple’s patent claims based on the new objections and decided there was a case to be made. That’s not quite the same as rejecting them. The burden now falls on Apple to defend its claims. Bottom line: With the barriers lowered and so much riding on the validity of Apple’s patents, we can expect more challenges in the future. “There will be some back-and-forth and some roller coaster rides,” writes FOSS Patents‘ Florian Mueller. “In the meantime, tentative rejections don’t affect the enforceability of a patent claim.” UPDATE: A reader with more knowledge of patent law than I has challenged the assertion that the America Invents Act had any effect on the the USPTO’s reexaminations of these particular Apple’s patents. He writes: [Post-grant review] proceedings are similar in their goal to ex parte reexaminations. Both are used to challenge a patent after it has been issued. There are currently a number of different mechanisms by which to challenge a patent after it has been issued, including ex parte reexamination, inter partes review, post grant review, and review of covered business method patents. The Apple patents were all challenged using ex parte reexamination requests filed around May I believe. The AIA did not substantively change ex parte reexaminations, other than the fees charged. Prior to Sept. 16, 2012, ex parte reexaminations cost $2520 in filing fees. Post Sept. 16, 2012, they cost $17,750 in filing fees. Post grant review (PGR) proceedings, which are discussed in the article you linked to, were not available until after Sept. 16, 2012 and were created by the passage of the AIA.