Fine. But we must still must be able to separate between backend and frontend: it should be possible to upgrade the anti-spam machinery without breaking - doub

Fine. But we must still must be able to separate between backend and frontend: it should be possible to upgrade the anti-spam machinery without breaking - doublequotes - + (ok, they broke that deliberately around Google+) - the verbatim operator All those should be able to work even if the crawler and processing techniques are updated, right? Also a heads up: I added some more details to my post above,I didn't think you would answer so fast :-) Edit: I only know the black hat methods that was well know 10 years ago like: - backlink farming from comment fields (we protected against it by applying nofollow to all links in comments) - Google bombing (coordinated efforts to link to certain pages with particular words in the link, trying to get Google to return a specific result for an unrelated query. I think the canonical example was something like a bunch of people making links with the text "a massive failure" that all pointed to the White house website. - Link-for-link schemes - etc