Federal Circuit case renders many broadly written software patents invalid
The court's opinion in this case (the <i>CyberSource</i> case) is at <a href="http://www.cafc.uscourts.gov/images/stories/opinions-orders/09-1358.pdf" rel="nofollow">http://www.cafc.uscourts.gov/images/stories/opinions-orders/...</a>.<p>Tl;dr:  The three-judge appeals court panel affirmed a summary judgment of invalidity. The panel announced a pretty straightforward test as one "filter" that can rule out patentability for certain claims:<p>1. If a method can be performed by the human mind alone, or with paper and pencil, then it's an "abstract idea," and therefore unpatentable under Supreme Court precedent.<p>2. If as a practical matter [a] the method <i>cannot</i> be performed with paper and pencil [b], then it passes the filter described in 1 above [c].<p>3. If a method would be unpatentable under 1 above, then a claim to a storage device encoding computer instructions for performing the method is likewise unpatentable.<p>NOTES:<p>[a] In its discussion, the court distinguished a couple of prior cases where such <i>non</i>-paper-and-pencil methods had been held patentable. See pages 20-21 of the PDF.  EDIT to respond to petegrif's comment below:  One of the earlier methods that had been ruled patentable was "for rendering a halftone image of a digital image by comparing, pixel by pixel, the digital image against a blue noise mask ...." The <i>CyberSource</i> panel distinguished this precedent by saying that, <i>as a practical matter,</i> that earlier method could <i>not</i> be performed by the human mind or with paper and pencil; see page 21 of the PDF.<p>[b] An unanswered question: How exactly are ordinary people supposed to determine whether a method can or can't be performed with paper and pencil "as a practical matter"?<p>[c] Even if a method gets past the "paper and pencil" filter, there are still other filters to pass before it will be patentable---but once the Patent and Trademark Office has issued the patent, then a presumption of patentability applies.<p>COMMENT: This is an area where the net effect of the precedents is not entirely clear. It wouldn't surprise me if the court were to take this case <i>en banc,</i> namely to have all of the court's 12 judges rehear and redecide the case in an attempt to clarify the law. (An <i>en banc</i> opinion is generally regarded as carrying more precedential weight than an opinion by a three-judge panel.)