> Essentially, a non-profit search engine would allow users to drive improvements to the algorithm by reporting bad results or collaborating on improvements. [...] I would envision a core team with many contributors - much like open-source projects hosted on Github.
I am absolutely sure that this will be abused. The (black hat) SEO is a huge industry, and it is continuously fighting to make search results worse for users. They did it before -- keywords meta does not work, simple pagerank no longer works, blog comments have NOFOLLOW and so on. It will be much worse in the proposed system -- the user votes will be faked, the good-looking commits will "by accident" drive up the position of specific websites, and so on.