The nofollow attribute is a way for site owners to say "I don't endorse this link". nofollow is very handy for site owners because it removes the incentive for

The nofollow attribute is a way for site owners to say "I don't endorse this link". nofollow is very handy for site owners because it removes the incentive for users to include spam links in user contributed content. However—and I think this is the point of the article—use of nofollow doesn't just disincentivise spam links, it also means that many valid and useful links no longer contribute to PageRank. It would be great if we could have a way to allow all to links contribute to PageRank, but still protect ourself from spam. Which got me thinking… At the moment the only options for site owners are to say "yes, I endorse this link" or "no, I don't endorse this link" (by adding nofollow). Instead I could imagine something more fine grained, a system where site owners could tag specific content within their site as coming from specific users. Content tagged like this is neither endorsed nor disavowed, instead responsibility is pushed to the user who wrote the content. In other words site owners would be able to say something like this to search engines: "this content is created by user X, don't blame me if it's spammy!". Smart search engines could use this more fine-grained content ownership information in their search algorithms. That means they wouldn't need to throw out all user contributed information on the internet just to protect the internet from spam. There are a few challenges, of course. :) * How to identify users? (Anonymously?) * How to have users endorse content on different sites? * How to work out which users are trustworthy? * Building a PageRank algorithm that incorporates fine-grained trust information. But it's fun to think about technical solutions.