[f_allwein]

I think a lot of this could simply be done on a domain level, i.e a site that publishes fake news once is likely to be generally less trustworthy. Then it would be up to sites like Google and FB to remove them from their listings (as is already done with spam) and not accept any ads linking to them (as is done for all kinds of illegal goods).

Come to think of it, even a site's PageRank should be a useful signal, as it (ideally) reflects the trust other sites have in this site.

[deepakravindran]

Our initial try was that by building a Chrome plugin called 'fakeornot' which will just tell you if its a fake site or not. But this was not working accurately as we saw sites like Mashable and others write articles which are not even verified and they quote to a source.