To help cut down on the appeal of MDN for spamming (especially profile spam), can we have rel=nofollow added to all external links?
I'm pretty sure that what is going on with the spamming on MDN is link/SEO farming, where the spammers think having links from a "legitimate" site like MDN to their spam pages boost their ranking in search engines. While we are deleting the pages as fast as we can, if google indexes them we could be penalized in our own rankings (for both the page content and the profile content). I know there is some concern with us not giving link "credit" to legitimate sites, so I was wondering if we could whitelist certain sites (e.g. wikipedia) or event admin users to have followable links, but plave nofollow on all other user-created links. This would be a P2, with the P1 being to stop giving spammers incentives to create the spam in the first place.
I agree that the character of the spam suggests link farming. Adding rel=nofollow does not seem like an immediate fix. It would require all of the people submitting spam to read the HTML source code of their newly created pages and change their behavior as a result. And that assumes people posting spam can read HTML and have the autonomy to change their targets -- too much to assume when we have more direct fixes at hand. I think we'll get a lot more short-term value from blocking questionable submissions (for example, by banning IPs or running new submissions through Akismet). Therefore I move to reduce the priority/importance of this and focus on more direct means of blocking first.
I suggested this to improve our SEO a few years back and it got batted down because we want places we cite to have SEO juice. We should focus on other methods of SPAM prevention, I would WONTFIX this one.
+1 to comment 3. In addition to the factors already mentioned, there is real uncertainty whether the attribute has much effect on search engine behavior. However, if this bug is reopened, then I think it needs a blocking bug for PR. We are not actually trying to change the amount of SEO juice in the world; we are trying to change a perception that MDN is an easy way to get SEO juice. A code change that may make MDN less valuable for SEO will be most effective if it is announced/publicized.  http://www.thoughtmechanics.com/does-nofollow-attribute-work-google-says-yes-studies-say-otherwise/