I'm not sure how PageRank always get brought up as the quintessential fair patent. Google most certainly didn't invent the eigenvector of stochastic matrices (a

I'm not sure how PageRank always get brought up as the quintessential fair patent. Google most certainly didn't invent the eigenvector of stochastic matrices (and if they did it wouldn't be patentable). The part of PageRank that's patentable seems mostly to be using hyperlinks as an input into known techniques. I don't think its obvious, but I don't think its a clear cut example of something that should be patentable either.