A pengiun recovery

Selected answers from the Dumb SEO Questions Facebook & G+ community.

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  W.E. Jonk: A pengiun recovery
  
  They did a lot. But what I found surprising was that they block visits from "spammy" sites and serve a 404 as a way to clean up. Personally I am not sure if this would work. And since they also removed/disavow links I am not sure if one can make a statement like that. What are your thoughts about this?
  
  http://www.boxaid.com/word/simple-alternative-google-disavow-tool/
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  George Dover: Wondering if anyone has had luck with using 404s instead of the *Google #disavowlinkstool  ;.  ;We did a little experiment on our site and it seems to be working well to get rid of spammy directories pointing to our site.  ;
  
  boxaid(dot)com/word/simple-alternative-google-disavow-tool/
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  Tony McCreath: I think it's quite clever. Especially because they identified the dodgy directories and only 404ed to them.
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  W.E. Jonk: But on the other hand if Googlebot is crawling through the link it would get a 404 where as if it would crawl through the Sitemap it would get a 200. Wouldn't that give mixed signals?
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  Matt Raynes: Would the mixed signal issue fall at the feet of the directory as opposed to where the link is arriving?
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  Tony McCreath: I think they were detecting the source IP and only 404ing if it was from a server they have associated with the directories they want to block. Kind of cloaking but targeting the directories and not googlebot. So The bots would still see the 200.
  
  A simpler way would be to just make all pages return the true content but a 404 for a period. Maybe do it in sections. Once the directories have removed the link you could revert back to a 200 and let the bots come back.
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  W.E. Jonk: +Matt Raynes ;I think I miss-read. Only the directory crawler gets a 404:
  
  So when the directory software does it’s header crawl it will most likely use this IP address.