View source for Admin:Link Spam

We have had a significant problem with [http://meatballwiki.org/wiki/LinkSpam Link Spam] on this wiki in recent months (late 2011).  We do not wish to prevent public contributions altogether, as any corrections to the [[Symbian OS Platform Security]] book are still very welcome and some new material is about to be added to the site which we hope will promote some public participation.

A while back we disabled anonymous article creation and added a [http://en.wikipedia.org/wiki/CAPTCHA CAPTCHA] to anonymous article edits, but that hasn't reduced the quantity of spam; it has continued to increase until we're deleting spam articles on an almost daily basis.  We are now taking the following steps:

;Disabling indexing and ranking of link spam
:On the basis that the motivation for link spam is to increase the [http://en.wikipedia.org/wiki/PageRank PageRank&#8482;] of the spammers' sites, we aim to make that ineffective by ensuring that the edits are not indexed by Google.  We have disabled indexing of all pages in the "Special:" name space, which includes the change history, using a [http://www.robotstxt.org/robotstxt.html site robots policy].  External links from this wiki are ignored for ranking due to the inclusion of the <code>[http://en.wikipedia.org/wiki/Nofollow nofollow]</code> attribute.  Indexing of deleted content from page histories is disabled using the [http://www.robotstxt.org/meta.html robots meta tag] with <code>noindex</code> and <code>nofollow</code>.
;Blocking references to known spam sites
:We have installed the [http://www.mediawiki.org/wiki/Extension:SpamBlacklist SpamBlacklist] MediaWiki extension.  This uses an [http://meta.wikimedia.org/wiki/Spam_blacklist actively maintained blacklist] to block edits containing URLs of sites included in spammed content.
;Looking for patterns in IP addresses used
:We have installed the [http://www.mediawiki.org/wiki/Extension:CheckUser CheckUser] MediaWiki extension.  This allows us to see the IP addresses used for page edits from logged-in users as well as anonymous users.  We intend to block IP addresses that are the source of repeated spam for much longer than the default autoblock period of 1 day.

The above measures have sadly not stemmed the rising tide of spam; we have now also disabled anonymous article edits, and new user accounts will require confirmation from an administrator.